Apparatus and method for transferring inflammable material on marine structure

ABSTRACT

A system for supplying fuel to an engine of a ship. The system includes a high pressure pump pressurizing a liquefied natural gas (LNG) and supplying the pressurized LNG to the engine, a hydraulic motor driving the high pressure pump and a chamber carrying the high pressure pump and the hydraulic motor. The chamber is substantially free of electric sparks.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND

Field

The present disclosure relates to a system for supplying fuel to anengine of a ship.

Discussion of Related Technology

Generally, heavy oil, such as marine diesel oil (MDO), has been used asfuel for engines of ships to propel the ships. In the case of burning,the heavy oil would create serious environmental contamination due tovarious harmful materials included in the exhaust of the heavy oil.Thus, regulations for various engines of ships using the heavy oil asfuel requires various measures which increase the price of ships andcosts for operating ships.

Therefore, proposed is the use of fuel gas, such as liquefied naturalgas (LNG), liquefied petroleum gas (LPG), compressed natural gas (CNG),and di-methyl ether (DME) in engines of ships as replacement of the fueloil. Further, in some instances, a ship includes both an engine thatuses fuel oil and another engine that uses fuel gas, operating theengines alternately during its voyage while considering costs andexhaust regulations.

The foregoing discussion in this section is to provide generalbackground information and does not constitute an admission of priorart.

SUMMARY

One aspect of the invention provides a ship, which may comprise: atleast one fuel tank containing fuel; a fuel pump in fluid communicationwith the at least one fuel tank and configured to pressurize fuel fromthe at least one fuel tank to a pressure in a range from 150 barabsolute (bar(a)) to 400 bar(a); a heater in fluid communication withthe fuel pump and configured to heat pressurized fuel from the fuel pumpto a supercritical state of the fuel; a supercritical fuel engine influid communication with the heater and configured to consume the fuelfrom the heater in its supercritical state; a hydraulic pump configuredto convert mechanical power into a pressurized flow of a hydraulicfluid; a hydraulic motor in fluid communication with the hydraulic pumpand configured to convert the pressurized flow from the hydraulic pumpinto torque to power the fuel pump; hydraulic fluid conduitsinterconnecting the hydraulic pump and the hydraulic motor to form aclosed loop of the hydraulic fluid; a fuel pump compartment enclosingthe fuel pump and the hydraulic motor such that fuel from the at leastone fuel tank is pressurized within the fuel pump compartment; a fuelprocessing compartment enclosing the heater such that the pressurizedfuel travels from the fuel pump compartment to the fuel processingcompartment and is heated within the fuel processing compartment; and ahydraulic pump compartment enclosing the hydraulic pump such that thehydraulic fluid is pressurized within the hydraulic pump compartment andsent to the fuel pump compartment; wherein the fuel pump compartment isair-tightly separated from the fuel processing compartment by at leastone air-tight wall such that the fuel pump and the hydraulic motor areair-tightly isolated from the heater, wherein the fuel pump compartmentis air-tightly separated from the hydraulic pump compartment by at leastone air-tight wall such that the fuel pump and the hydraulic motor areair-tightly isolated from the hydraulic pump.

In the foregoing ship, the fuel pump compartment may comprise a firstair inlet configured to receive air from outside the ship and a firstair outlet configured to discharge air from the fuel pump compartment,wherein the air from the outside the ship is to enter the fuel pumpcompartment through the first air inlet without mixing with air fromanother compartment of the ship. The fuel processing compartment maycomprise a second air inlet configured to receive air from outside theship and a second air outlet configured to discharge air from the fuelprocessing compartment, wherein the air from the outside the ship is toenter the fuel processing compartment through the second air inletwithout mixing with air from another compartment of the ship. The shipmay further comprise: a first air intake conduit configured to receiveair from outside the ship and transfer the air to the first air inlet;and a second air intake conduit configured to receive air from outsidethe ship and transfer the air to the second air inlet, wherein the firstand second air intake conduits are separate from each other and are notinterconnected. The ship may further comprise a first air dischargeconduit configured to receive air from the first air outlet of the fuelpump compartment to outside the ship; a first leak detector configuredto be exposed to the air discharged from the fuel pump compartment andto detect leakage of fuel within the fuel pump compartment; a second airdischarge conduit configured to receive air from the second outlet ofthe fuel processing compartment outside the ship; and a second leakdetector configured to be exposed to air discharged from the fuelprocessing compartment and to detect leakage of fuel within the fuelpump compartment.

Still in the foregoing ship, the fuel pump and the hydraulic motorenclosed in the fuel pump compartment may be built in an integratedbody, wherein the fuel pump comprises a piston and arotation-to-reciprocation converter configured to convert torque fromthe hydraulic motor to reciprocating motion of the piston. The heatermay comprise a heat exchanger configured to heat the pressurized fuelfrom the fuel pump, wherein the hydraulic pump comprises an electricmotor configured to generate mechanical energy to power pumping togenerate the pressurized flow of hydraulic fluid.

Yet in the foregoing ship, the ship may comprise a hull and a deckplaced over the hull, wherein the fuel processing compartment and thehigh-pressure pump compartment are located above the deck of the ship,wherein the hydraulic pump compartment is located under the deck. Theship may comprise a hull and a deck placed over the hull, wherein thefuel processing compartment and the fuel pump compartment are adjacentto each other and separated by the at least one wall without anyintervening compartment or cofferdam between the fuel pump compartmentand the fuel processing compartment, wherein a down-stream line from thefuel pump to the heater pass through the at least one wall. The ship mayfurther comprise a cofferdam or another distinct compartment interposedbetween the fuel pump compartment and the hydraulic pump compartment,wherein the hydraulic fluid conduits pass through the cofferdam or theother distinct compartment. The ship may further comprise a cofferdaminterposed between the fuel pump compartment and the hydraulic pumpcompartment, wherein the hydraulic fluid conduits does not pass throughthe cofferdam and instead goes around the cofferdam, wherein the fuelprocessing compartment and the fuel pump compartment are adjacent toeach other and separated by the at least one wall only without anyintervening compartment or cofferdam between the fuel pump compartmentand the fuel processing compartment, wherein a down-stream line from thefuel pump to the heater does not pass through the at least one wall andinstead goes around the at least one wall such that the down-stream linepasses through another wall of the fuel pump compartment and anotherwall of the fuel processing compartment.

Further in the foregoing ship, the ship may further comprise: avaporizer in fluid communication with the at least one fuel tank andconfigured to vaporize the fuel from the at least one fuel tank; and avapor fuel engine in fluid communication with the vaporizer andconfigured to consume the fuel from the vaporizer in its vapor state,wherein the vaporizer is enclosed in the fuel processing compartment,wherein the fuel from the at least one fuel tank is transferred to thevaporizer without going through the fuel pump compartment. The ship mayfurther comprise a mist separator in fluid communication with thevaporizer and configured to remove mists contained in the fuel from thevaporizer before the fuel is sent to the vapor fuel engine, wherein thevaporizer comprises a heat exchanger configured to heat the fuel fromthe at least one fuel tank to provide the vaporized state of the fuel,wherein the mist separator is also enclosed in the fuel processingcompartment. The supercritical fuel engine may comprise an M-typeElectronic Gas Injection (MEGI) engine, wherein the vapor fuel enginemay comprise a dual-fuel diesel-electric (DFDE) engine.

Still further in the foregoing ship, the ship may further comprise alubricant pump configured to pump lubricant to either or both of thefuel pump and the hydraulic motor enclosed in the fuel pump compartment,wherein the lubricant pump is enclosed in or outside the fuel pumpcompartment. The ship may further comprise: a lubricant pump configuredto pump lubricant to either or both of the fuel pump and the hydraulicmotor enclosed in the fuel pump compartment; a secondary hydraulic pumpcomprising an electric motor and configured to convert torque from theelectric motor into a pressurized flow of a hydraulic fluid; and asecondary hydraulic motor in fluid communication with the secondaryhydraulic pump and configured to convert the pressurized flow from thesecondary hydraulic pump into torque to power the lubricant pump,wherein the lubricant pump is enclosed in the fuel pump compartment,wherein the secondary hydraulic pump is enclosed in the hydraulic pumpcompartment, wherein the secondary hydraulic motor is enclosed in thefuel pump compartment. The ship may further comprise: lubricant conduitsin fluid communication with the hydraulic pump and configured to supplyat least part of the fluid as lubricant to either or both of the fuelpump and the hydraulic motor, wherein the lubricant conduits passthrough at least one air-tight wall; and a lubricant pump configured topump the lubricant to send the lubricant to either or both of the fuelpump and the hydraulic motor enclosed in the fuel pump compartment,wherein the lubricant pump is located outside the fuel pump compartment.

Another aspect of the invention provides a ship, which may comprise: atleast one fuel tank containing fuel; a fuel pump in fluid communicationwith the at least one fuel tank and configured to pressurize fuel fromthe at least one fuel tank to a pressure in a range from 150 barabsolute (bar(a)) to 400 bar(a); a heater in fluid communication withthe fuel pump and configured to heat pressurized fuel from the fuel pumpto a supercritical state of the fuel; a supercritical fuel engine influid communication with the heater and configured to consume the fuelfrom the heater in its supercritical state; at least one hydraulic pumpconfigured to convert mechanical power into a pressurized flow of ahydraulic fluid; a first hydraulic motor in fluid communication with theat least one hydraulic pump and configured to convert the pressurizedflow from the at least one hydraulic pump into torque to power the fuelpump; a lubricant pump configured to pump lubricant to either or both ofthe fuel pump and the hydraulic motor; a second hydraulic motor in fluidcommunication with the at least one hydraulic pump and configured toconvert the pressurized flow from the at least one hydraulic pump intotorque to power the lubricant pump; hydraulic fluid conduitsinterconnecting the at least one hydraulic pump and the first and secondhydraulic motors; a fuel pump compartment comprising multiple air-tightwalls and enclosing the fuel pump, the first hydraulic motor and thelubricant pump and the second hydraulic motor; and at least onehydraulic pump compartment enclosing the at least one hydraulic pump,wherein the fuel pump compartment is air-tightly separated from the atleast one hydraulic pump compartment such that the fuel pump, the firsthydraulic motor, the lubricant pump and the second hydraulic motor areair-tightly isolated from the at least one hydraulic pump.

In the foregoing ship, the at least one hydraulic pump may comprise afirst hydraulic pump and a second hydraulic pump, which are enclosed ina single hydraulic pump compartment or in two separate hydraulic pumpcompartments, wherein the first hydraulic pump is in fluid communicationwith the first hydraulic motor via part of the hydraulic fluid conduitsto form a first closed loop of hydraulic fluid, wherein the secondhydraulic pump is in fluid communication with the second hydraulic motorvia part of the hydraulic fluid conduits to form a second closed loop ofhydraulic fluid. The at least one hydraulic pump may be a singlehydraulic pump, wherein the at least one hydraulic pump compartment is asingle hydraulic pump compartment, wherein the single hydraulic pump isin fluid communication with the first and second hydraulic motors viathe hydraulic fluid conduits. The ship may further comprise lubricantconduits interconnecting between the lubricant pump and the fuel pump toform a closed loop of lubricant flow, wherein the lubricant conduits areenclosed in the fuel pump compartment. The ship may further compriselubricant conduits interconnecting between the lubricant pump and thehydraulic motor to form a closed loop of lubricant flow, wherein thelubricant conduits are enclosed in the fuel pump compartment.

Still in the foregoing ship, the hydraulic fluid conduits may extendbetween the fuel pump compartment and the at least one hydraulic pumpcompartment through at least one of the multiple air-tight walls of thefuel pump compartment. The ship may further comprise an electric motorconfigured to generate mechanical energy to power the at least onehydraulic pump for pumping of hydraulic fluid in the at least onehydraulic pump, wherein the electric motor is integrated with the atleast one hydraulic pump and enclosed in the at least one hydraulic pumpcompartment. The fuel pump and the hydraulic motor enclosed in the fuelpump compartment may be built in an integrated body, wherein thelubricant pump configured to pump lubricant to the integrated body.

Yet in the foregoing ship, the ship may further comprise a hydraulicfluid container enclosed in the at least one hydraulic pump compartmentand in fluid communication with the at least one hydraulic pump. Theship may further comprise a hydraulic fluid drain conduitinterconnecting the first hydraulic motor and the hydraulic fluidcontainer, wherein the hydraulic fluid drain conduit extends between thefuel pump compartment and the at least one hydraulic pump compartment.The supercritical fuel engine may comprise an M-type Electronic GasInjection (MEGI) engine. The ship may further comprise a fuel processingcompartment enclosing the heater such that the pressurized fuel travelsfrom the fuel pump compartment to the fuel processing compartment and isheated within the fuel processing compartment, wherein the fuel pumpcompartment is air-tightly separated from the fuel processingcompartment by at least one air-tight wall such that the fuel pump andthe first hydraulic motor are air-tightly isolated from the heater,

Still another aspect of the invention provides a ship, which maycomprise: at least one fuel tank containing fuel; a fuel pump in fluidcommunication with the at least one fuel tank and configured topressurize fuel from the at least one fuel tank to a pressure in a rangefrom 150 bar absolute (bar(a)) to 400 bar(a); a heater in fluidcommunication with the fuel pump and configured to heat pressurized fuelfrom the fuel pump to a supercritical state of the fuel; a supercriticalfuel engine in fluid communication with the heater and configured toconsume the fuel from the heater in its supercritical state; a hydraulicpump configured to convert mechanical power into a pressurized flow of ahydraulic fluid; a hydraulic motor in fluid communication with thehydraulic pump and configured to convert the pressurized flow from thehydraulic pump into torque to power the fuel pump; hydraulic fluidconduits interconnecting the hydraulic pump and the hydraulic motor toform a closed loop of the hydraulic fluid; a vaporizer in fluidcommunication with the at least one fuel tank and configured to vaporizethe fuel from the at least one fuel tank; and a vapor fuel engine influid communication with the vaporizer and configured to consume thefuel from the vaporizer in its vapor state; a fuel pump compartmentenclosing the fuel pump and the hydraulic motor; a fuel processingcompartment enclosing the heater and the vaporizer; and wherein the fuelpump compartment and the fuel processing compartment are air-tightlyseparated by at least one partitioning wall therebetween such that thefuel pump is air-tightly isolated from the heater and the vaporizer.

In the foregoing ship, the fuel pump compartment may comprise a firstair inlet configured to receive air from outside the ship and a firstair outlet configured to discharge air from the fuel pump compartment,wherein the air from the outside the ship is to enter the fuel pumpcompartment through the first air inlet without mixing with air fromanother compartment of the ship. The fuel processing compartment maycomprise a second air inlet configured to receive air from outside theship and a second air outlet configured to discharge air from the fuelprocessing compartment, wherein the air from the outside the ship is toenter the fuel processing compartment through the second air inletwithout mixing with air from another compartment of the ship. The shipmay further comprise: a first air intake conduit configured to receiveair from outside the ship and transfer the air to the first air inlet;and a second air intake conduit configured to receive air from outsidethe ship and transfer the air to the second air inlet, wherein the firstand second air intake conduits are separate from each other and are notinterconnected.

Still in the foregoing ship, the fuel pump compartment may comprise afirst air inlet configured to receive air from outside the ship and afirst air outlet configured to discharge air from the fuel pumpcompartment to outside the ship, wherein the air from the fuel pumpcompartment to the outside the ship is to be discharged to outside theship without mixing with air from another compartment of the ship. Thefuel processing compartment may comprise a second air inlet configuredto receive air from outside the ship and a second air outlet configuredto discharge air from the fuel processing compartment to outside theship, wherein the air from the fuel processing compartment to theoutside the ship is to be discharged to outside the ship without mixingwith air from another compartment of the ship. The ship may furthercomprise: a first air discharge conduit configured to receive air fromthe first air outlet of the fuel pump compartment to outside the ship; afirst leak detector configured to be exposed to the air discharged fromthe fuel pump compartment and to detect leakage of fuel within the fuelpump compartment; a second air discharge conduit configured to receiveair from the second outlet of the fuel processing compartment outsidethe ship; and a second leak detector configured to be exposed to airdischarged from the fuel processing compartment and to detect leakage offuel within the fuel pump compartment. The first and second airdischarge conduits may be separate from each other and are notinterconnected such that the first leak detector detects the fuelincluded in air from the fuel pump compartment that is not mixed withair from the fuel processing compartment, and further such that thesecond leak detector detects the fuel included in air from the fuelprocessing compartment that is not mixed with air from the fuel pumpcompartment.

Yet in the foregoing ship, the ship may further comprise a hydraulicpump compartment enclosing the hydraulic pump, wherein the fuel pumpcompartment is separated from the hydraulic pump compartment by at leastone air-tight wall such that the fuel pump and the hydraulic motor areair-tightly isolated from the hydraulic pump. The ship may furthercomprise an electric motor configured to generate mechanical energy topower the at least one hydraulic pump for pumping of hydraulic fluid inthe at least one hydraulic pump, wherein the electric motor isintegrated with the hydraulic pump and enclosed in the hydraulic pumpcompartment. The ship may further comprise a mist separator in fluidcommunication with the vaporizer and configured to remove mistscontained in the fuel from the vaporizer before the fuel is sent to thevapor fuel engine, wherein the vaporizer comprises a heat exchangerconfigured to heat the fuel from the at least one fuel tank to providethe vaporized state of the fuel, wherein the mist separator is alsoenclosed in the fuel processing compartment.

Further in the foregoing ship, the heater may comprise a first heatexchanger configured to heat the pressurized fuel being transferredbetween the fuel pump and the supercritical fuel engine, wherein thevaporizer comprises a second heat exchanger configured to heat the fueltransferred from the at least one fuel tank to provide the vaporizedstate of the fuel, wherein the ship further comprises a heat medium flowcircuit connected to the first and second heat exchangers, the heatmedium flow circuit being configured to circulate a heat medium heatedby heat originated from either or both of the supercritical fuel engineand the vapor fuel engine. The heat medium flow circuit may be enclosedin the fuel processing compartment, wherein the fuel pump is air-tightlyisolated from the first and second heat exchangers and a heat transfermedium flow circuit. The supercritical fuel engine may comprise anM-type Electronic Gas Injection (MEGI) engine, wherein the vapor fuelengine comprises a dual-fuel diesel-electric (DFDE) engine or a gasturbine engine. The fuel in a vapor state being transferred from thevaporizer and the vapor fuel engine may have a pressure of about 6bar(a) to about 10 bar(a). The ship may comprise a hull and a deckplaced over the hull, wherein the fuel processing compartment and thefuel pump compartment are located above the deck of the ship, whereinthe hydraulic pump compartment is located under the deck.

A further aspect of the invention provides a ship, which may comprises:a fuel tank containing fuel; a fuel pump in fluid communication with thefuel tank and configured to pressurize fuel from the fuel tank to apressure in a range from 150 bar absolute (bar(a)) to 400 bar(a); aheater in fluid communication with the fuel pump and to heat pressurizedfuel from the fuel pump to a supercritical state of the fuel; asupercritical fuel engine in fluid communication with the heater andconfigured to consume the fuel from the heater in its supercriticalstate; a hydraulic pump configured to convert mechanical power into apressurized flow of a hydraulic fluid; a hydraulic motor in fluidcommunication with the hydraulic pump and configured to convert thepressurized flow from the hydraulic pump into torque to power the fuelpump; hydraulic fluid conduits interconnecting the hydraulic pump andthe hydraulic motor to form a closed loop of the hydraulic fluid; a fuelpump compartment air-tightly partitioned from one or more neighboringcompartments by at least one partitioning wall, wherein the fuel pumpand the hydraulic motor are enclosed in the fuel pump compartment andthe heater and the hydraulic pump are not enclosed in the fuel pumpcompartment such that that the high-pressure pump is air-tightlyisolated from the hydraulic pump.

The present disclosure relates to an apparatus and method for stablytransferring an inflammable material on a marine structure, and moreparticularly, to an apparatus and method for transferring an inflammablematerial, which can stably transfer an inflammable material such asliquefied natural gas (LNG) using a hydraulic motor as a drive sourcefor operating a compressor or a pump when transferring the inflammablematerial on a marine structure, thereby stably transferring theinflammable material without risk of explosion or fire.

Another aspect of the invention provides an apparatus and method fortransferring an inflammable material on a marine structure, which canstably transfer an inflammable material such as liquefied natural gas(LNG) using a hydraulic motor as a drive source for operating acompressor or a pump when transferring the inflammable material on amarine structure, thereby stably transferring the inflammable materialwithout risk of explosion or fire. The apparatus includes apressurization unit placed in a danger zone and pressurizing theinflammable material to transfer the inflammable material in onedirection; and a hydraulic motor driving the pressurization unit,wherein the hydraulic motor and the pressurization unit are placedtogether in the danger zone.

According to one aspect of the invention, an apparatus for transferringan inflammable material on a marine structure, which is used to transferan inflammable material from one place to another place on the marinestructure, includes: a pressurization unit pressurizing the inflammablematerial to transfer the inflammable material in one direction; and ahydraulic motor driving the pressurization unit, wherein the hydraulicmotor and the pressurization unit are placed in the same place.

Supply of operating fluid to the hydraulic motor may be performed by adedicated hydraulic pressure generator for the hydraulic motor. Ahydraulic line may be disposed between the dedicated hydraulic pressuregenerator and the hydraulic motor to supply the operating fluid to thehydraulic motor therethrough. The dedicated hydraulic pressure generatormay include two hydraulic pumps for redundancy. The pressurization unitmay include a pump or a compressor.

The apparatus according to embodiments of the invention may furtherinclude a lubricant pump for supplying a lubricant to the hydraulicmotor. The lubricant pump may be placed together with the hydraulicmotor in the same space. The apparatus according to embodiments of theinvention may further include a hydraulic motor for the lubricant pumpto drive the lubricant pump. The lubricant pump and the hydraulic motorfor the lubricant pump may be placed together with the hydraulic motorin the same space.

The lubricant may be supplied into the hydraulic motor through alubricant supply line extending from the lubricant pump to the hydraulicmotor and then returned to the lubricant pump through a lubricant returnline extending from the hydraulic motor to the lubricant pump.

Supply of operating fluid to the hydraulic motor and the hydraulic motorfor the lubricant pump may be performed by a dedicated hydraulicpressure generator. The dedicated hydraulic pressure generator mayinclude: a first hydraulic pump for supplying the operating fluid to thehydraulic motor; a second hydraulic pump for supplying the operatingfluid to the hydraulic motor for the lubricant pump; and a reservoircapable of storing the operating fluid.

The operating fluid stored in the reservoir may be supplied to thehydraulic motor through a first supply line after being compressed bythe first hydraulic pump and then returned to the reservoir through afirst return line, and may be supplied to the hydraulic motor for thelubricant pump through a second supply line after being compressed bythe second hydraulic pump and then returned to the reservoir through asecond return line.

The apparatus according to embodiments of the invention may furtherinclude a first drain line to discharge the entirety of the operatingfluid from the hydraulic motor for maintenance and overhaul of thehydraulic motor.

The apparatus according to embodiments of the invention may furtherinclude: a lubricant pump for supplying a lubricant to the hydraulicmotor; a hydraulic motor for the lubricant pump for driving thelubricant pump; and a second drain line to discharge the entirety of theoperating fluid from the hydraulic motor for the lubricant pump formaintenance and overhaul of the hydraulic motor for the lubricant pump.

The operating fluid used for driving the hydraulic motor may be used asa lubricant supplied for lubrication of the hydraulic motor. Supply ofthe operating oil to the hydraulic motor and supply of the lubricant tothe hydraulic motor may be performed by the dedicated hydraulic pressuregenerator. The dedicated hydraulic pressure generator may include afirst hydraulic pump for supplying the operating fluid to the hydraulicmotor, a second hydraulic pump for supplying the lubricant to thehydraulic motor, and a reservoir capable of storing the operating fluid.

The operating fluid stored in the reservoir may be supplied to thehydraulic motor through a first supply line to operate the hydraulicmotor after being compressed by the first hydraulic pump and thenreturned to the reservoir through a first return line, and may besupplied as a lubricant to the hydraulic motor through a second supplyline after being compressed by the second hydraulic pump and thenreturned to the reservoir through a second return line.

The apparatus according to embodiments of the invention may furtherinclude: a first drain line to discharge the entirety of the operatingfluid from the hydraulic motor for maintenance and overhaul of thehydraulic motor, and a lubricant drain line to discharge the entirety ofthe lubricant from the hydraulic motor for maintenance and overhaul ofthe hydraulic motor.

According to one aspect of the invention, a method of transferring aninflammable material from one place to another place on a marinestructure, includes: operating a hydraulic motor with a hydraulicpressure supplied from a hydraulic pressure generator; and operating apressurization unit pressurizing the inflammable material through adrive shaft extending from the hydraulic motor to transfer theinflammable material in one direction, wherein the hydraulic motor andthe pressurization unit are placed together in the same place.

Embodiments of the invention provide an apparatus for transferring aninflammable material, which employs a hydraulic motor not causinggeneration of electric sparks as a driving source for the transferapparatus, and a method for transferring an inflammable material. As aresult, the apparatus and method for transferring an inflammablematerial according to the embodiments of the invention can guaranteestable transfer of the inflammable material.

In addition, in the apparatus and method for transferring an inflammablematerial according to the embodiments of the invention, which employsthe hydraulic motor, a pressurization unit for pressurizing aninflammable material and a drive unit for operating the pressurizationunit, that is, the hydraulic motor, are placed in the same space,thereby facilitating axial alignment and providing advantages in termsof maintenance and space utilization, as compared with a transferapparatus in which the pressurization unit and the drive unit are placedin different spaces.

Furthermore, in the apparatus and method for transferring an inflammablematerial according to the embodiments of the invention, the hydraulicmotor having a smaller size than an electric motor is used instead ofthe electric motor, whereby the apparatus and method for transferring aninflammable material can be easily applied to a medium or small marinestructure having a narrower installation space than a large marinestructure.

The present disclosure further relates to a ship using a liquefiednatural gas (LNG) as a fuel, and more particularly, to an apparatus anda method for supplying a fuel to an engine of a ship and an apparatusand a method for regulating a speed of a high pressure pump supplyingLNG to an engine.

Another aspect of the invention provides an apparatus and a method forsupplying a fuel to an engine of a ship. The apparatus for supplying afuel to an engine of a ship includes: a high pressure pump pressurizinga liquefied natural gas (LNG) and supplying the pressurized LNG to theengine; a hydraulic motor driving the high pressure pump; and alubricating pump supplying lubricating oil to the high pressure pump.

An aspect of the invention is to provide an apparatus for supplying afuel to an engine of a ship capable of miniaturizing and lightening alldevices for supplying a fuel to an engine and being installed in anexplosion-proof zone without an additional device to supply power andlubricating oil to a high pressure pump, and a method for supplying afuel to an engine of a ship using the same.

Another aspect of the invention is to provide an apparatus forregulating a speed of a high pressure pump capable of miniaturizing andlightening all devices supplying a fuel to an engine and being installedin an explosion-proof zone without an additional device, and a methodfor regulating a speed of a high pressure pump using the same.

According to an embodiment of the invention, there is provide anapparatus for supplying a fuel to an engine of a ship, including: a highpressure pump pressurizing a liquefied natural gas (LNG) and supplyingthe pressurized LNG to the engine; a hydraulic motor driving the highpressure pump; and a lubricating pump supplying lubricating oil to thehigh pressure pump.

The apparatus for supplying a fuel to an engine of a ship may furtherinclude first and second hydraulic power units supplying oil to thehydraulic motor, wherein the second hydraulic power unit is operated inthe case in which the first hydraulic power unit is not operable.

The first hydraulic power unit may be connected to the hydraulic motorby a first hydraulic line on which a first shutdown valve is installed,the second hydraulic power unit may be connected to the hydraulic motorby a second hydraulic line on which a second shutdown valve isinstalled, and the first shutdown valve may be opened in the case inwhich the first hydraulic power unit is operated and the second shutdownvalve may be opened in the case in which the second hydraulic power unitis operated.

The apparatus for supplying a fuel to an engine of a ship may furtherinclude a pressure gauge installed in the first hydraulic line andmeasuring a pressure of the first hydraulic line. The apparatus forsupplying a fuel to an engine of a ship may further include alubricating motor driving the lubricating pump. The apparatus forsupplying a fuel to an engine of a ship may further include third andfourth hydraulic power units supplying oil to the lubricating motor,wherein the fourth hydraulic power unit is operated in the case in whichthe third hydraulic power unit is not operable.

The third hydraulic power unit may be connected to the lubricating motorby a third hydraulic line on which a third shutdown valve is installed,the fourth hydraulic power unit may be connected to the lubricatingmotor by a fourth hydraulic line on which a fourth shutdown valve isinstalled, and the third shutdown valve may be opened in the case inwhich the third hydraulic power unit is operated and the fourth shutdownvalve may be opened in the case in which the fourth hydraulic power unitis operated.

The apparatus for supplying a fuel to an engine of a ship may furtherinclude a hydraulic power unit supplying oil to the hydraulic motor andthe lubricating motor. The hydraulic power unit may be connected to thelubricating motor by a hydraulic line on which a pressure regulatingvalve is installed, and the pressure regulating valve may be a valveregulating an amount of oil supplied to the lubricating motor.

According to another embodiment of the invention, an apparatus forsupplying a fuel to an engine of a ship, includes: a high pressure pumppressurizing an LNG and supplying the pressurized LNG to the engine; ahydraulic motor driving the high pressure pump; a first hydraulic powerunit supplying oil to the hydraulic motor; and a second hydraulic powerunit supplying oil to the hydraulic motor in the case in which the firsthydraulic power unit is not operable.

The first hydraulic power unit may be connected to the hydraulic motorby a first hydraulic line on which a first shutdown valve is installed,the second hydraulic power unit may be connected to the hydraulic motorby a second hydraulic line on which a second shutdown valve isinstalled, and the first shutdown valve may be opened in the case inwhich the first hydraulic power unit is operated and the second shutdownvalve may be opened in the case in which the second hydraulic power unitis operated. The apparatus for supplying a fuel to an engine of a shipmay further include a pressure gauge installed in the first hydraulicline and measuring a pressure of the first hydraulic line.

According to still another embodiment of the invention, an apparatus forregulating a speed of a high pressure pump of a ship includes: ahydraulic motor driving the high pressure pump while regulating thespeed of the high pressure pump; a hydraulic power unit including afixed displacement type hydraulic pump and a reservoir storing oiltherein and regulating an amount of oil supplied to the hydraulic motorto regulate the speed of the hydraulic motor; and a recirculation valveallowing a portion of the oil transferred from the reservoir by thefixed displacement type hydraulic pump to again flow to the reservoir.

The recirculation valve may be installed inside the hydraulic powerunit. The recirculation valve may be installed outside the hydraulicpower unit. The high pressure pump may pressurize an LNG and supply thepressurized LNG to an engine.

According to yet still another embodiment of the invention, a method forregulating a speed of a high pressure pump of a ship includes:transferring oil stored in a reservoir toward a hydraulic line connectedto a hydraulic motor using a fixed displacement type hydraulic pump;regulating a recirculation valve installed on a hydraulic line branchedfrom the hydraulic line to regulate an amount of oil supplied to thehydraulic motor, thereby regulating a speed of the hydraulic motor; andallowing the speed of the high pressure pump to be regulated dependingon the regulation of the speed of the hydraulic motor.

The fixed displacement type hydraulic pump and the reservoir may beincluded in a hydraulic power unit, and the recirculation valve may beinstalled inside the hydraulic power unit. The fixed displacement typehydraulic pump and the reservoir may be included in a hydraulic powerunit, and the recirculation valve may be installed outside the hydraulicpower unit. The high pressure pump may pressurize an LNG and supply thepressurized LNG to an engine.

The present disclosure further relates to an apparatus for stablysupplying fuel gas to an engine in a vessel, and more particularly, to afuel gas supply apparatus in which, in a vessel having a high-pressureengine and a low-pressure engine, a high-pressure pump of a fuel gassupply system for supplying fuel gas to the high-pressure engine isdisposed in a separate space, thereby minimizing an influence on theoverall fuel gas supply system even upon leakage of the fuel gas.

Another aspect of the invention provides a fuel gas supply apparatus forsupplying fuel gas to an engine disposed in a vessel. The fuel gassupply apparatus includes: a gas supply system provided to a gas supplyline for supplying fuel gas to the engine; a pump and a gasificationunit included in the gas supply system; and a partition wallpartitioning a space in which the gas supply system is disposed into afirst space and a second space, wherein at least part of the pump isdisposed in the first space.

An aspect of the invention provides a fuel gas supply apparatus, inwhich a separate space is defined by a partition wall such that a pump,through which fuel gas such as LNG can leak during transfer in a vesselis disposed therein, thereby stably transferring the fuel gas withoutrisk of explosion or fire.

In accordance with one aspect of the invention, a fuel gas supplyapparatus for supplying fuel gas to an engine disposed in a vesselincludes: a gas supply system provided to a gas supply line forsupplying fuel gas to the engine; a pump and a gasification unitincluded in the gas supply system; and a partition wall partitioning aspace in which the gas supply system is disposed into a first space anda second space, wherein at least part of the pump is disposed in thefirst space.

The pump and the gasification unit may be disposed together in the firstspace. The gasification unit may be disposed in the second space. Thepump may include a pumping unit pressurizing and discharging anintroduced fuel gas, a drive unit driving the pumping unit, and aconnecting shaft interconnecting the pumping unit and the drive unit totransmit power therebetween. The pumping unit may be disposed in thefirst space and the drive unit may be disposed in the second space. Theconnecting shaft may connect the pumping unit and the drive unit througha bearing disposed in the partition wall. The gasification unit may bearranged together with the drive unit in the second space.

The engine may include a low-pressure engine requiring a lower fuelsupply pressure and a high-pressure engine requiring a higher fuelsupply pressure. The gas supply line may include a low-pressure gassupply line for supplying fuel gas to the low-pressure engine and alow-pressure gas supply line for supplying fuel gas to the high-pressureengine. The gas supply system may include a low-pressure gas supplysystem provided to the low-pressure gas supply line and a high-pressuregas supply system provided to the high-pressure gas supply line. Thepump may be a high-pressure pump that is included in the high-pressuregas supply system to pressurize the fuel gas to a fuel supply pressurerequired for the high-pressure engine. The gasification unit may includea low-pressure gasification unit included in the low-pressure gas supplysystem and a high-pressure gasification unit included in thehigh-pressure gas supply system.

The low-pressure gasification unit of the low-pressure gas supply systemmay be disposed in the second space, and the high-pressure pump and thehigh-pressure gasification unit of the high-pressure gas supply systemmay be disposed in the first space. The low-pressure gasification unitof the low-pressure gas supply system and the high-pressure gasificationunit of the high-pressure gas supply system may be disposed in thesecond space and the high-pressure pump of the high-pressure gas supplysystem may be disposed in the first space.

Embodiments of the invention provide a fuel gas supply apparatus, inwhich a separate space is defined by a partition wall such that a pump,through which fuel gas such as LNG can leak during transfer in a vessel,can be disposed therein.

According to the embodiments of the invention, it is possible to stablytransfer fuel gas without risk of explosion or fire. In addition, as thepump is disposed in the separate space, even though fuel gas leaksthrough a sealing portion of the pump, other facilities disposed in thevessel to supply fuel gas are not affected by the leaked fuel gas andthus, products of a low explosion proof grade can be used for thefacilities disposed in the separate space from the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by an electric motor.

FIG. 2 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

FIG. 3 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

FIG. 4 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

FIG. 5 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

FIG. 6 is a view showing an example of an apparatus for supplying a fuelto an engine of a ship according to an embodiment of the invention;

FIG. 7 is a view showing another example of an apparatus for supplying afuel to an engine of a ship according to an embodiment of the invention;

FIG. 8 is a view showing still another example of an apparatus forsupplying a fuel to an engine of a ship according to an embodiment ofthe invention;

FIG. 9 is a view showing an example of an apparatus for regulating aspeed of a high pressure pump of a ship according to an embodiment ofthe invention;

FIG. 10 is a view showing another example of an apparatus for regulatinga speed of a high pressure pump of a ship according to an embodiment ofthe invention;

FIG. 11 is a view showing still another example of an apparatus forregulating a speed of a high pressure pump of a ship according to anembodiment of the invention;

FIG. 12 is a flow chart showing an example of a method for regulating aspeed of a high pressure pump of a ship according to an embodiment ofthe invention;

FIG. 13 is a flow chart showing another example of a method forregulating a speed of a high pressure pump of a ship according to anembodiment of the invention;

FIG. 14 is a diagram of a fuel gas supply apparatus in a vessel having ahigh-pressure engine and a low-pressure engine therein.

FIG. 15 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention.

FIG. 16 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention.

FIG. 17 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention.

FIG. 18 shows a ship with a fuel supply system according to embodimentsof the invention.

FIG. 19 shows components of the fuel supply system enclosed incompartments of the ship shown in FIG. 18.

FIG. 20 is a sectional view of a ship taken along a line XX-XX of FIG.19.

FIG. 21 is a sectional view of a ship taken along a line XXI-XXI of FIG.20.

DETAILED DESCRIPTION OF EMBODIMENTS

Various embodiments are discussed below in detail.

Generally, in recent years, the use of liquefied natural gas (LNG) orliquefied petroleum gas (LPG) has rapidly expanded throughout the world.Liquefied gas is transported in a gaseous state through onshore oroffshore gas pipelines, or transported to a remote consumption sitewhile being stored in a liquefied state inside a liquefied gas carrier.Liquefied gas, such as LNG or LPG, is obtained by cooling natural gas orpetroleum gas to cryogenic temperatures (in the case of LNG, about −163°C.). Since the volume of liquefied gas is considerably reduced ascompared to a gaseous state, liquefied gas is suitable for long-distancemarine transportation.

A liquefied gas carrier is designed to load liquefied gas, sail acrossthe sea, and unload the liquefied gas at an onshore consumption site. Tothis end, the liquefied gas carrier includes a storage tank (also calleda “cargo hold”) that can withstand cryogenic temperatures of liquefiedgas.

Examples of a marine structure provided with a storage tank capable ofstoring cryogenic liquefied gas may include vessels, such as a liquefiedgas carrier and an LNG re-gasification vessel (LNG RV), or plants suchas an LNG floating storage and re-gasification unit (LNG FSRU), an LNGfloating, production, storage and off-loading (LNG FPSO) unit, and abarge mounted power plant (BMPP).

An LNG RV is a self-propelled, floating liquefied natural gas carrierequipped with an LNG re-gasification facility. An LNG FSRU is a marinestructure that stores LNG unloaded from an LNG carrier on the sea faraway from the land and, if necessary, supplies the LNG to an onshoreconsumption site by gasifying the LNG, and an LNG FPSO unit is a marinestructure that refines extracted LNG at sea, stores the LNG in a storagetank after direct liquefaction, and, if necessary, transships the LNG toan LNG carrier. A BMPP is a structure that produces electricity at seausing a power plant mounted on a barge.

Herein, “vessel” or “marine structure” includes off-shore plants, suchas an LNG FPSO, an Oil FPSO, an LNG FSRU, and a BMPP, as well as aliquefied gas carrier and an LNG RV.

Since LNG is inflammable, a region where LNG is likely to be introducedis designated as a danger zone in a marine structure or vesseltransporting or using LNG. In the danger zone, explosion prooffacilities are used to prevent explosion or fire in the case of possibleintroduction of liquefied natural gas.

In particular, when heavy fuel oil or marine diesel oil (MDO) used as afuel of an engine in a vessel is combusted, serious environmentalpollution is caused by harmful materials contained in exhaust gas.Therefore, restrictions on an engine of a vessel that uses oil as afuel, such as heavy fuel oil, are being increased and costs required forsatisfying the restrictions are increasingly rising.

Accordingly, engines using a clean fuel gas, such as LNG, LPG, CNG, orDME are developed and installed in various marine structures or vessels,and replace engines using heavy fuel oil or MDO as a fuel.

However, a clean fuel gas, such as LNG, is inflammable and, when used asa fuel in an engine for propulsion or power generation, needs to beconsistently supplied to the engine during operation of a marinestructure. Therefore, stability and safety of inflammable materialtransfer facilities would become important.

By the way, the International Maritime Organization (IMO) regulates theemission of nitrogen oxides (NO_(X)) and sulfur oxides (SO_(X)) amongexhaust gases of vessels and these days, also tries to regulate theemission of carbon dioxide (CO₂). Particularly, the issue of theregulation of nitrogen oxides (NO_(X)) and sulfur oxides (SO_(X)) wasraised by the Prevention of Marine Pollution from Ships (MARPOL)protocol in 1997. After eight years, the protocol met requirements foreffectuation and entered into force in May 2005. Currently, theregulation is in force as a compulsory provision.

Therefore, in order to meet such provisions, a variety of methods havebeen introduced to reduce the emission of nitrogen oxides (NO_(X)). Asone of these methods, a high-pressure natural gas injection engine for amarine structure such as an LNG carrier, for example, an MEGI engine(M-type, Electronically-Controlled, Gas-Injection engine) has beendeveloped and used. The MEGI engine is being spotlighted as anext-generation eco-friendly engine capable of reducing emission ofcarbon dioxide by 23% or more, nitrogen compounds by 80% or more, andsulfur compounds by 95% or more, as compared with a diesel engine havingthe same output.

Such an MEGI engine may be provided in plants or vessels such as an LNGcarrier which transports LNG while storing the LNG in a storage tankcapable of withstanding cryogenic temperatures. In this case, the MEGIengine uses natural gas as fuel and requires a high pressure of about200 to 400 bara (absolute pressure) for gas supply, depending upon aload thereof.

The MEGI engine may be directly coupled to a propeller for propulsionand to this end, may be a two-stroke engine rotating at a low speed.That is, the MEGI engine is a low-speed two-stroke high-pressure naturalgas injection engine.

As sued herein, a transfer apparatus may be provided to a fuel gassupply (FGS) system for supplying fuel gas to the MEGI engine.

As used herein, the term “marine structure” is a concept includingplants, such as an LNG FPSO, an Oil FPSO, an LNG FSRU, and a BMPP, aswell as vessels, such as a liquefied gas carrier, an LNG RV, and acontainer ship.

In addition, as used herein, the term “inflammable material” is aconcept including a gas that is stored as cargo in a storage tank andsupplied to an engine when necessary, as well as a gas that is stored ina fuel tank for fuel supply to various types of engines provided to avessel for propulsion and power generation.

Further, as used herein, the term “space” means a zone divided by apartition wall, and the expression “placed in the same space” can beinterpreted as meaning that at least two components are placed togetherin one zone divided by a partition wall.

FIG. 1 shows one embodiment of an apparatus for transferring aninflammable material such as LNG on a marine structure. The transferapparatus shown in FIG. 1 employs an electric motor as a driving source.

Referring to FIG. 1, the transfer apparatus for transferring aninflammable material such as LNG or boil-off gas, and includes apressurization unit 10 provided to a transfer pipe 2 in a pressurizingspace (zone 0) 1 and pressurizing the inflammable material to transferthe inflammable material through the transfer pipe 2 in one direction,and an electric motor 12 placed in an adjacent space (zone 1) 3, whichis adjacent the pressurizing space 1 designated as a danger zone due torisk of explosion and divided by a partition wall 4, and provided as adrive unit for operating the pressurization unit 10.

As used herein, the term “pressurizing space” means a space in which thepressurization unit 10 is placed to pressurize the inflammable materialfor transfer of the inflammable material, and the term “adjacent space”means a space near the “pressurizing space” with a partition wallinterposed therebetween. The pressurizing space must be designated as adanger zone in which explosion is likely to occur due to leakage of theinflammable material from the pressurization unit.

As the pressurization unit 10, a pump may be used when transferring aninflammable liquid material such as LNG, and a compressor may be usedwhen transferring an inflammable gaseous material such as boil-off gas(BOG).

As a pump room or a compressor room, the pressurizing space or room 1 isa zone in which explosion is likely to occur due to leakage of theinflammable material and thus installation of equipment usingelectricity that can cause spark generation is avoided.

On the other hand, as the drive unit for the pressurization unit, theelectric motor may be an explosion-proof electric motor. However, evenwhen the explosion-proof electric motor is used as the electric motor,the electric motor may be placed in another space excluding a spacehaving a possibility of leakage of the inflammable material (that is,the pressurizing space 1) in order to secure safety.

Accordingly, the electric motor 12 operated by electricity may be placedin the adjacent space or room 3 that acts as a motor room divided fromthe pressurizing space 1 by the partition wall 4, and drive force of theelectric motor 12 is transmitted to the pressurization unit 10 through adriving shaft 13 passing through the partition wall 4. Supply ofelectricity to the electric motor 12 may be achieved by a powergenerator 15 disposed (in a safety zone) outside the motor room.

A portion of the partition wall 4 through which the driving shaft 13passes may be sealed by a sealing bearing member 5 to block inflow ofthe inflammable material therethrough.

In such a structure of the transfer apparatus of the inflammablematerial, the electric motor can be placed in a separate space dividedfrom the pressurization unit by the partition wall, thereby enablingsafe transfer of the inflammable material.

However, in the transfer apparatus as shown in FIG. 1, thepressurization unit 10 and the electric motor 12 are placed in separatespaces with the partition wall 4 interposed therebetween, and areconnected to each other through the driving shaft 13, thereby requiringconsiderable time and endeavor for alignment of the driving shaft 13upon installation of the pressurization unit 10 and the electric motor12 in the corresponding spaces.

Moreover, the adjacent space 3, which adjoins the pressurizing space 1having a possibility of leakage of the inflammable material, requires anexhaust device 17 in order to discharge the inflammable material in theevent that the inflammable material leaks to the adjacent space, therebycausing deterioration in space utilization due to difficulty in sizereduction of the adjacent space 3 provided as the motor room.

Next, the configuration and operation of transfer apparatuses accordingto embodiments of the invention will be described in more detail withreference to FIG. 2 and FIG. 3. It should be understood that thefollowing embodiments may be modified in various ways and do not limitthe scope of the invention.

FIG. 2 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

Referring to FIG. 2, an apparatus for transferring an inflammablematerial such as LNG or boil-off gas includes a pressurization unit 10provided to a transfer pipe 2 in a pressurizing space (zone 0) 1 andpressurizing the inflammable material to transfer the inflammablematerial through the transfer pipe 2 in one direction, and a hydraulicmotor 20 placed together with the pressurization unit 10 in thepressurizing space 1 and serving as a drive unit for operating thepressurization unit 10.

As the pressurization unit 10, a pump may be used when transferring aninflammable liquid material such as LNG, and a compressor may be usedwhen transferring an inflammable gaseous material such as boil-off gas(BOG).

As a pump room or a compressor room, the pressurizing space 1 is a zonein which explosion is likely to occur due to leakage of the inflammablematerial and thus installation of equipment using electricity that cancause spark generation is avoided. However, the hydraulic motor 20 doesnot use electricity and thus can be provided to the pressurizing space1.

In this way, the apparatus and method for transferring inflammablematerial according to embodiments of the invention employs the hydraulicmotor instead of the electric motor 12 as the drive unit for operatingthe pressurization unit 10 such as the pump or the compressor disposedin the pressurizing space 1, thereby providing advantages in terms ofmaintenance and space utilization without installing the electric motorin the pressurizing space 1 in which explosion is likely to occur due toleakage of the inflammable material.

A driving shaft 21 is connected between the hydraulic motor 20 and thepressurization unit 10 to transmit drive force of the hydraulic motor 20to the pressurization unit 10 therethrough.

Supply of operating fluid to the hydraulic motor 20 may be simplyperformed by a hydraulic pressure generator disposed inside the marinestructure. According to this embodiment, however, the transfer apparatusmay be provided with a dedicated hydraulic pressure generator 23 fordriving the pressurization unit 10 of the inflammable material such thatthe operating fluid can be supplied to the hydraulic motor 20 through ahydraulic line 25 extending between the dedicated hydraulic pressuregenerator 23 and the hydraulic motor 20.

The dedicated hydraulic pressure generator 23 may include two hydraulicpumps 24 for redundancy.

The hydraulic motor 20 according to this embodiment may be a speedvariable hydraulic motor. Use of the speed variable hydraulic motoreliminates a need for a separate speed reduction device and providesadvantages in that the speed variable hydraulic motor occupies a smallinstallation space and allows easy maintenance and overhaul, as comparedwith the electric motor that requires the reduction device such as areduction gear and the like.

FIG. 3 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

Like the transfer apparatus according to the embodiment of FIG. 2, theapparatus for transferring an inflammable material according to theembodiment shown in FIG. 3 includes a pressurization unit 10 provided toa transfer pipe 2 in a pressurizing space (zone 0) 1 and pressurizingthe inflammable material to transfer the inflammable material throughthe transfer pipe 2 in one direction, and a hydraulic motor 20 placedtogether with the pressurization unit 10 in the pressurizing space 1 andserving as a drive unit for operating the pressurization unit 10.

As the pressurization unit 10, a pump may be used when transferring aninflammable liquid material such as LNG, and a compressor may be usedwhen transferring an inflammable gaseous material such as boil-off gas(BOG).

According to this embodiment, the apparatus and method for transferringinflammable material employs the hydraulic motor instead of the electricmotor 12 as the drive unit for operating the pressurization unit 10 suchas the pump or the compressor disposed in the pressurizing space 1 usedas a pump room or a compressor room, thereby providing advantages interms of maintenance and space utilization without installing theelectric motor in the pressurizing space 1.

Now, different features between the embodiment and the embodiment willbe mainly described. In the following description, like components willbe denoted by like reference numerals and detailed descriptions thereofwill be omitted.

The apparatus for transferring an inflammable material according to theembodiment may further include a partition wall 6 that divides thepressurizing space 1 into at least two spaces. Among the two spacesdivided by the partition wall 6, one space receiving the pressurizationunit 10 must be treated as a danger zone in which explosion is likely tooccur. Further, the other space opposite the space receiving thepressurization unit 10 with reference to the partition wall 6 may betreated as an adjacent space 7 near the pressurizing space 1corresponding to the danger zone. In embodiment, the room 1 isgas-tightly separated from the room 7, and the partition wall 6 is agas-tight wall to inhibit air or gas in the room 1 from flowing into theroom 7 through the partition wall 6.

The adjacent space or room 7 may be provided with various devices 8 thatcannot be disposed in the pressurizing space 1 due to risk of explosion.For example, the devices 8 placed in the adjacent space 7 includevarious devices associated with supply of fuel gas to engines, units forcontrolling such devices, and the like.

The apparatus for transferring an inflammable material according to thisembodiment may be placed on a deck 31, and the hydraulic pressuregenerator 23 configured to supply the operating fluid to the hydraulicmotor 20 may be disposed in an engine room (or machinery room) 32 underthe deck 31. In embodiment, the room 1 is gas-tightly separated from theroom 32, and the deck 31 includes a gas-tight wall structure, forexample, a cofferdam, between the room 1 and the engine room 32 toinhibit the air or gas in the room 1 from flowing into the engine room32.

In FIG. 3, the transfer pipe 2 extends upwards from a lower side of thedeck 31 through the pressurizing space 1. However, it should beunderstood that this configuration is provided for illustration only andthe invention is not limited to the extending directions of the transferpipe 2 as shown in FIGS. 2 and 3.

FIG. 4 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

Like the transfer apparatus according to the embodiment of FIG. 2, theapparatus for transferring an inflammable material according to theembodiment shown in FIG. 4 includes a pressurization unit 10 provided toa transfer pipe 2 in a pressurizing space (zone 0) 1 and pressurizingthe inflammable material to transfer the inflammable material throughthe transfer pipe 2 in one direction, and a hydraulic motor 20 placedtogether with the pressurization unit 10 in the pressurizing space 1 andserving as a drive unit for operating the pressurization unit 10.

As the pressurization unit 10, a pump may be used when transferring aninflammable liquid material such as LNG, and a compressor may be usedwhen transferring an inflammable gaseous material such as boil-off gas(BOG).

As a pump room or a compressor room, the pressurizing space 1 is a zonein which explosion is likely to occur due to leakage of the inflammablematerial and thus installation of equipment using electricity that cancause spark generation is avoided. However, the hydraulic motor 20 doesnot use electricity and thus can be provided to the pressurizing space1.

In this way, the apparatus and method for transferring inflammablematerial according to embodiments of the invention employs the hydraulicmotor instead of the electric motor 12 as the drive unit for operatingthe pressurization unit 10 such as the pump or the compressor disposedin the pressurizing space 1, thereby providing advantages in terms ofmaintenance and space utilization without installing the electric motorin the pressurizing space 1 in which explosion is likely to occur due toleakage of the inflammable material.

A driving shaft 21 may be connected between the hydraulic motor 20 andthe pressurization unit 10 to transmit drive force of the hydraulicmotor 20 to the pressurization unit 10 therethrough.

Unlike the transfer apparatus according to the embodiment, the apparatusfor transferring an inflammable material according to the embodimentshown in FIG. 4 further includes a lubricant pump 40 that supplies alubricant to the hydraulic motor 20 disposed in the pressurizing space1, and a hydraulic motor 50 for the lubricant pump that drives thelubricant pump 40 and is placed together with the hydraulic motor 20 inthe pressurizing space 1.

In order to guarantee efficient driving of the hydraulic motor 20, thereis a need for lubrication between respective components in motion. Inaddition, when the inflammable material is LNG, the LNG has a cryogenictemperature of about 163° C. at room temperature and affects thetemperature of the pressurization unit 10 such that the temperature ofthe pressurization unit 10 is significantly lowered. As a result, thehydraulic motor 20 placed near the pressurization unit 10 and connectedthereto by the driving shaft 21 can be also affected by low temperature.Since the viscosity of the lubricant increases at a low surroundingtemperature, there can be a need for circulation of the lubricant due toinsufficient lubrication.

In this embodiment, since the hydraulic motor 20 is connected to thepressurization unit 10, which pressurizes the inflammable material,through the driving shaft 21, a structure in which the lubricant iscirculated is more advantageous than a structure in which the lubricantstagnates in the hydraulic motor 20. To this end, the lubricant pump 40and the hydraulic motor 50 for the lubricant pump are respectivelyseparated from the pressurization unit 10 and the hydraulic motor 20within the pressurizing space 1.

As in the embodiment in which the driving shaft 21 is connected betweenthe hydraulic motor 20 and the pressurization unit 10 to transmit driveforce from the hydraulic motor 20 to the pressurization unit 10, adriving shaft 51 is connected between the hydraulic motor 50 and thelubricant pump 40 to transmit drive force from the hydraulic motor 50 tothe lubricant pump 40.

For lubrication between the respective components of the hydraulic motor20, a lubricant may be supplied into the hydraulic motor 20 through alubricant supply line 41 extending from the lubricant pump 40 to thehydraulic motor 20, and then returned to the lubricant pump 40 through alubricant return line 42 extending from the hydraulic motor 20 to thelubricant pump 40.

Supply of operating fluid to the hydraulic motor 20 and the hydraulicmotor 50 for the lubricant pump may be simply performed by a hydraulicpressure generator disposed inside the marine structure. In addition,according to this embodiment, the transfer apparatus may be providedwith a dedicated hydraulic pressure generator 53 for the hydraulic motor20 for driving the pressurization unit 10 of the inflammable materialand the hydraulic motor 50 for driving the lubricant pump 40 such thatthe operating fluid can be supplied to the hydraulic motor 20 and thehydraulic motor 50 for the lubricant pump.

The dedicated hydraulic pressure generator 53 includes a first hydraulicpump 24 that supplies the operating fluid to the hydraulic motor 20, asecond hydraulic pump 54 that supplies the operating fluid to thehydraulic motor 50 for the lubricant pump, and a reservoir 52 capable ofstoring the operating fluid.

The dedicated hydraulic pressure generator 53 may include two firsthydraulic pumps 24 having the same specifications and provided forredundancy.

The operating fluid stored in the reservoir 52 may be supplied to thehydraulic motor 20 through a first supply line 25 to operate thehydraulic motor 20 after being compressed by the first hydraulic pump24, and then returned to the reservoir 52 through a first return line26. As needed, some or the entirety of the operating fluid flowingtowards the reservoir through the first return line 26 may be directlysupplied to an upstream side of the first hydraulic motor 24 of thefirst supply line 25 without passing through the reservoir 52.

In addition, the operating fluid stored in the reservoir 52 may besupplied to the hydraulic motor 50 for the lubricant pump through asecond supply line 55 to operate the hydraulic motor 50 for thelubricant pump after being compressed by the second hydraulic pump 54,and then returned to the reservoir 52 through a second return line 56.As needed, some or the entirety of the operating fluid flowing towardsthe reservoir 52 through the second return line 56 may be directlysupplied to an upstream side of a second hydraulic motor 54 of thesecond supply line 55 without passing through the reservoir 52.

According to this embodiment, the apparatus for transferring aninflammable material may be provided with a first drain line 27 todischarge the entirety of the operating fluid from the hydraulic motor20 for maintenance and overhaul of the hydraulic motor 20. The firstdrain line 27 may extend from the hydraulic motor 20, particularly froma lower end of the hydraulic motor 20, to the reservoir 52 or to theoutside of the hydraulic pressure generator 53. The first drain line 27is provided with a valve 28, which is opened to drain the operatingfluid from the hydraulic motor 20 towards the reservoir 52 only upondrainage.

In addition, according to this embodiment, the apparatus fortransferring an inflammable material may be provided with a second drainline 57 to discharge the entirety of the operating fluid from thehydraulic motor 50 for maintenance and overhaul thereof. The seconddrain line 57 may extend from the hydraulic motor 50 for the lubricantpump, particularly from a lower end of the hydraulic motor 50 for thelubricant pump, to the reservoir 52 or to the outside of the hydraulicpressure generator 53. The second drain line 57 is provided with a valve58, which is opened to drain the operating fluid from the hydraulicmotor 50 towards the reservoir 52 only upon drainage.

The hydraulic motor 20 and the hydraulic motor 50 for the lubricant pumpaccording to this embodiment may be speed variable hydraulic motors. Useof the speed variable hydraulic motors eliminates a need for a separatespeed reduction device and provides advantages in that the speedvariable hydraulic motors occupy a small installation space and alloweasy maintenance and overhaul, as compared with the electric motor thatrequires the reduction device such as a reduction gear and the like.

FIG. 5 is a diagram of an apparatus for transferring an inflammablematerial, which is driven by a hydraulic motor, according to anembodiment of the invention.

Like the transfer apparatus according to the embodiment of FIG. 4, theapparatus for transferring an inflammable material according to theembodiment shown in FIG. 5 includes a pressurization unit 10 provided toa transfer pipe 2 in a pressurizing space (zone 0) 1 and pressurizingthe inflammable material to transfer the inflammable material throughthe transfer pipe 2 in one direction, and a hydraulic motor 20 placedtogether with the pressurization unit 10 in the pressurizing space 1 andserving as a drive unit for operating the pressurization unit 10.

As the pressurization unit 10, a pump may be used when transferring aninflammable liquid material such as LNG, and a compressor may be usedwhen transferring an inflammable gaseous material such as boil-off gas(BOG).

As a pump room or a compressor room, the pressurizing space 1 is a zonein which explosion is likely to occur due to leakage of the inflammablematerial and thus installation of equipment using electricity that cancause spark generation is avoided. However, the hydraulic motor 20 doesnot use electricity and thus can be provided to the pressurizing space1.

In this way, the apparatus and method for transferring inflammablematerial according to embodiments of the invention employs the hydraulicmotor instead of the electric motor 12 as the drive unit for operatingthe pressurization unit 10 such as the pump or the compressor disposedin the pressurizing space 1, thereby providing advantages in terms ofmaintenance and space utilization without installing the electric motorin the pressurizing space 1 in which explosion is likely to occur due toleakage of the inflammable material.

A driving shaft 21 may be connected between the hydraulic motor 20 andthe pressurization unit 10 to transmit drive force of the hydraulicmotor 20 to the pressurization unit 10 therethrough.

Unlike the transfer apparatus according to the embodiment, the transferapparatus according to the embodiment employs operating fluid, which canbe used to drive the hydraulic motor 20, as a lubricant for thehydraulic motor 20. Accordingly, the transfer apparatus according to theembodiment does not require the lubricant pump 40 and the hydraulicmotor 50 for the lubricant pump, which are used in the transferapparatus according to the embodiment.

On the other hand, supply of the operating fluid to the hydraulic motor20 may be simply performed by a hydraulic pressure generator disposedinside the marine structure. In addition, according to this embodiment,the transfer apparatus may be provided with a dedicated hydraulicpressure generator 53 for supply of a lubricant for the hydraulic motor20 for driving the pressurization unit 10 of the inflammable materialsuch that the operating fluid and the lubricant can be supplied to thehydraulic motor 20 by the dedicated hydraulic pressure generator 53.

The dedicated hydraulic pressure generator 53 includes a first hydraulicpump 24 that supplies the operating fluid to the hydraulic motor 20, asecond hydraulic pump 54 that supplies the operating fluid as alubricant to the hydraulic motor 20, and a reservoir 52 capable ofstoring the operating fluid.

The hydraulic pressure generator 53 may include two first hydraulicpumps 24 having the same specifications and provided for redundancy.

The operating fluid stored in the reservoir 52 may be supplied to thehydraulic motor 20 through a first supply line 25 to operate thehydraulic motor 20 after being compressed by the first hydraulic pump24, and then returned to the reservoir 52 through a first return line26. As needed, some or the entirety of the operating fluid flowingtowards the reservoir 52 through the first return line 26 may bedirectly supplied to upstream of the first hydraulic motor 24 of thefirst supply line 25 without passing through the reservoir 52.

In addition, the operating fluid stored in the reservoir 52 may besupplied as a lubricant to the hydraulic motor 20 through a secondsupply line 55 to operate the hydraulic motor 20 after being compressedby the second hydraulic pump 54, and then returned to the reservoir 52through a second return line 56. As needed, some or the entirety of theoperating fluid flowing towards the reservoir 52 through the secondreturn line 56 may be directly supplied to upstream of a secondhydraulic motor 54 of the second supply line 55 without passing throughthe reservoir 52.

According to this embodiment, the apparatus for transferring aninflammable material may be provided with a first drain line 27 todischarge the entirety of the operating fluid from the hydraulic motor20 for maintenance and overhaul of the hydraulic motor 20. The firstdrain line 27 may extend from the hydraulic motor 20, particularly froma lower end of the hydraulic motor 20, to the reservoir 52 or to theoutside of the hydraulic pressure generator 53. The first drain line 27is provided with a valve 28, which is opened to drain the operatingfluid from the hydraulic motor 20 towards the reservoir 52 only upondrainage.

In addition, according to this embodiment, the apparatus fortransferring an inflammable material may be provided with a lubricantdrain line 67 to discharge the entirety of the lubricant from thehydraulic motor 20 for maintenance and overhaul of the hydraulic motor20. The lubricant drain line 67 may extend from the hydraulic motor 20,particularly from a lubricant circulation unit inside the hydraulicmotor 20, to the reservoir 52 or to the outside of the hydraulicpressure generator 53. The lubricant drain line 67 is provided with avalve 68, which is opened to drain the operating fluid used as thelubricant from the hydraulic motor 20 towards the reservoir 52 only upondrainage.

The hydraulic motor 20 according to this embodiment may be a speedvariable hydraulic motor. Use of the speed variable hydraulic motoreliminates the need for a separate speed reduction device and providesadvantages in that the speed variable hydraulic motor occupies a smallinstallation space and allows easy maintenance and overhaul, as comparedwith the electric motor that requires the reduction device such as areduction gear and the like.

With the structure as described above, the apparatus for transferring aninflammable material employs a hydraulic motor not causing generation ofelectric sparks as a driving source for the transfer apparatus, therebyguaranteeing stable transfer of the inflammable material without risk ofexplosion or a fire.

In addition, in the apparatus and method for transferring an inflammablematerial according to the invention, which employs the hydraulic motor,a pressurization unit for pressurizing an inflammable material and adrive unit for operating the pressurization unit, that is, the hydraulicmotor, are placed in the same space, thereby facilitating axialalignment and providing advantages in terms of maintenance and spaceutilization, as compared with a transfer apparatus in which thepressurization unit and the drive unit are placed in different spaces.

Further, in the apparatus and method for transferring an inflammablematerial according to embodiments of the invention, the hydraulic motorhaving a smaller size than an electric motor is used instead of theelectric motor, whereby the apparatus and method for transferring aninflammable material can be easily applied to a medium or small marinestructure having a narrower installation space than a large marinestructure.

Furthermore, when the apparatus and the method according to embodimentsof the invention are applied to cargo vessels such as LNG carriers,container ships, and the like, the size of a space allocated to theapparatus for transferring an inflammable material can be significantlyreduced, thereby allowing increase in cargo carrying capacitycorresponding to reduction in the size of the space.

In the case of a main engine (MEGI) using the LNG as a fuel, a supplycondition of high pressure (200 to 300 barg) has been demanded, and ahigh pressure pump and a high pressure vaporizer have been used in orderto satisfy this condition.

In order to drive the high pressure pump, an electric motor or ahydraulic motor may be used. However, the United State Coast Guard(USCG) has defined a zone in which the high pressure pump is present asan explosion-proof zone to prohibit the electric motor from being usedin this zone, and has defined so as to install a partition wall betweenthe high pressure pump and the electric motor in order to use theelectric motor. Therefore, in the case of using the electric motor, thepartition wall should be separately installed. In addition, lubricatingoil should be supplied to the high pressure pump in order to smoothlydrive a driving part for a long period of time.

Meanwhile, in the case of the main engine, a fuel supply system that maybe driven by the LNG at a low speed as well as at a high speed has beenrecently demanded, which means that a load of the engine may besignificantly variably driven.

In terms of the fuel supply system, the system should be configured soas to variably satisfy a fuel supply amount by the load of the mainengine. In order to supply the fuel so as to be in accord with an amountof fuel required by the engine, a speed of the high pressure pump shouldbe regulated. The motor is installed in order to drive the high pressurepump. According to the related art, the electric motor and a variablefrequency drive (VFD) are installed, and the VFD regulates a frequencysupplied to the electric motor to regulate a speed of the electricmotor.

However, the USCG has defined a zone in which the high pressure pump ispresent as an explosion-proof zone to prohibit the electric motor frombeing used in this zone, and has defined so as to install a partitionwall between the high pressure pump and the electric motor in order touse the electric motor. Therefore, in the case of using the electricmotor, the partition wall should be separately installed.

Generally, a nitrogen oxide (NOx) and a sulfur oxide (SOx) among wastegases drained from a ship have been regulated by the InternationalMaritime Organization. Recently, discharge of a carbon dioxide has alsobeen regulated. Particularly, the regulation for the nitrogen oxide(NOx) and the sulfur oxide (SOx) was imposed through a protocol of theprevention of marine pollution from ships (MARPOL) in 1997, and aneffectuation requirement for the regulation for the nitrogen oxide (NOx)and the sulfur oxide (SOx) was satisfied in May, 2005, which is a timeafter a long time of eight years elapses, such that the regulation forthe nitrogen oxide (NOx) and the sulfur oxide (SOx) has been currentlyeffected as a compulsory rule.

Therefore, various methods for decreasing a drain amount of nitrogenoxide (NOx) have been introduced in order to satisfy the above-mentionedrule. Among them, a high pressure natural gas injection engine for amarine structure including a ship, or the like, such as a liquefiednatural gas (LNG) carrier, for example, an MEGI engine has beendeveloped and used. The MEGI engine has been prominent as theenvironment-friendly next generation engine that may decrease a drainamount of carbon dioxide, which is a pollutant, by 23% or more, a drainamount of nitrogen compound, which is a pollutant, by 80% or more, and adrain amount of sulfur compound, which is a pollutant, by 95% or more,as compared with a diesel engine having the same level of output.

The MEGI engine as described above may be installed in the ship such asthe LNG carrier storing LNG in a storage tank enduring a very lowtemperature and carrying the LNG or the marine structure such as variousplants, or the like. In this case, a natural gas is used as a fuel of anengine, and a high fuel gas supply pressure of about 200 to 400 bara(absolute pressure) is required in the engine depending on a load of theengine.

The MEGI engine may be used in a state in which it is directly connectedto a propeller for propulsion. To this end, the MEGI engine isconfigured of a two-stroke engine rotated at a low speed. That is, theMEGI engine is a low speed two-stroke high pressure natural gasinjection engine.

Since a zone in which a high pressure pump is present is anexplosion-proof zone, it is dangerous to operate the high pressure pumpusing an electric motor. In addition, lubricating oil should be suppliedto the high pressure pump in order to smoothly drive a driving part ofthe high pressure pump for a long period of time. Therefore, in anembodiment of the invention, the high pressure pump is driven using ahydraulic motor, and the lubricating oil is supplied to the highpressure pump using a lubricating motor and a lubricating pump.

FIG. 6 is a view showing an example of an apparatus for supplying a fuelto an engine of a ship according to an embodiment of the invention; andFIG. 7 is a view showing another example of an apparatus for supplying afuel to an engine of a ship according to an embodiment of the invention.

As shown in FIGS. 6 and 7, the apparatus for supplying a fuel to anengine of a ship according to an embodiment of the invention isconfigured to include a high pressure pump 170 pressurizing a liquefiednatural gas (LNG) and supplying the pressurized LNG to the engine, ahydraulic motor 120 driving the high pressure pump 170, a lubricatingpump 140 supplying lubricating oil to the high pressure pump 170, and alubricating motor 110 driving the lubricating pump 140.

The hydraulic motor 120 is connected to the high pressure pump 170 todrive the high pressure pump 170. A driving shaft is connected betweenthe hydraulic motor 120 and the high pressure pump 170, and drivingforce of the hydraulic motor 120 may be transferred to the high pressurepump 170 through the driving shaft.

Since a zone in which the high pressure pump 170 is present is a dangerzone in which the possibility of explosion is present, a device usingelectricity, which may cause a spark, may not be installed in the dangerzone in order to secure safety. Therefore, in an embodiment of theinvention, the hydraulic motor 120 rather than an electric motor is usedas a driving apparatus of the high pressure pump 170, which isadvantageous in terms of maintenance and space utilization withoutinstalling the electric motor in the danger zone.

A hydraulic power unit 130 is a device supplying oil to the hydraulicmotor 120 in order to drive the hydraulic motor 120.

The hydraulic power unit 130 includes a hydraulic pump 131 and areservoir 132. The reservoir 132 is a storage tank storing the oiltherein. As shown in FIGS. 6 and 7, the hydraulic motor 120 and thereservoir 132 are connected to each other by a hydraulic line, and thehydraulic pump 131 is installed on the hydraulic line through which theoil flows from the reservoir 132 to the hydraulic motor 120. Thehydraulic pump 131 supplies the oil stored in the reservoir 132 to thehydraulic motor 120, and the oil drives the hydraulic motor 120 and thenflows again into the reservoir 132 through the hydraulic line.

The lubricating pump 140 supplies the lubricating oil to the highpressure pump 170. The lubricating pump 140 supplies the lubricating oilstored in a lubricating oil reservoir 150 to the high pressure pump 170,and since a temperature of the lubricating oil drained from the highpressure pump 170 rises, the lubricating oil drained from the highpressure pump 170 is cooled using a cold coolant in a cooler 160 andthen enters again the lubricating oil reservoir 150.

The lubricating pump 140 is driven by the lubricating motor 110. Adriving shaft connected between the lubricating motor 110 and thelubricating pump 140, and driving force of the lubricating motor 110 maybe transferred to the lubricating pump 140 through the driving shaft.

The lubricating motor 110 is driven by the oil supplied thereto by thehydraulic power unit 130.

As shown in FIGS. 6 and 7, the lubricating motor 110 and the reservoir132 of the hydraulic power unit 130 are connected to each other by ahydraulic line, and the hydraulic pump 131 is installed on the hydraulicline through which the oil flows from the reservoir 132 to thelubricating motor 110. The hydraulic pump 131 supplies the oil stored inthe reservoir 132 to the lubricating motor 110, and the oil drives thelubricating motor 110 and then flows again into the reservoir 132through the hydraulic line.

As shown in FIG. 6, each of the lubricating motor 110 and the hydraulicmotor 120 may be connected to two hydraulic power units 130.

That is, since the hydraulic motor 120 is connected to the two hydraulicpower units 130, in the case in which one of the two hydraulic powerunits 130 may not be operated due to a fault, or the like, the other ofthe two hydraulic power units 130 is operated to supply the oil to thehydraulic motor 120, such that the hydraulic motor 120 may becontinuously operated normally.

In addition, since the lubricating motor 110 is also connected to thetwo hydraulic power units 130, in the case in which one of the twohydraulic power units 130 may not be operated due to a fault, or thelike, the other of the two hydraulic power units 130 is operated tosupply the oil to the lubricating motor 110, such that the lubricatingmotor 110 may be continuously operated normally.

As shown in FIG. 6, a shutdown valve 180 is installed on each of thehydraulic line connecting the hydraulic motor 120 and the hydraulicpower unit 130 to each other and the hydraulic line connecting thelubricating motor 110 and the hydraulic power unit 130 to each other.When the hydraulic power unit 130 connected to the hydraulic line onwhich the corresponding shutdown valve 180 is installed is operated, thecorresponding shutdown valve 180 is opened, and when the hydraulic powerunit 130 connected to the hydraulic line on which the correspondingshutdown valve 180 is installed is not operated, the correspondingshutdown valve 180 is closed.

That is, in the case in which a first hydraulic power unit 130 and asecond hydraulic power unit 130 are connected to the hydraulic motor120, the shutdown valve 180 installed on the hydraulic line connected tothe first hydraulic power unit 130 is opened during a period in whichthe first hydraulic power unit 130 is operated, and the shutdown valve180 installed on the hydraulic line connected to the first hydraulicpower unit 130 is closed and the shutdown valve 180 installed on thehydraulic line connected to the second hydraulic power unit 130 isopened when a fault occurs in the first hydraulic power unit 130, suchthat the second hydraulic power unit 130 is operated.

In addition, a pressure gauge 190 is installed on the hydraulic line tosense whether or not a fault has occurred in the hydraulic power unit130. The pressure gauge 190 includes a pressure transmitter 191 and apressure indicator 192. The pressure transmitter 191 measures a pressureof the hydraulic line and transmits the measured pressure to thepressure indicator 192, and the pressure indicator 192 indicates thereceived pressure. When the pressure indicated by the pressure gauge 190exceeds a normal range, it is judged that a fault has occurred in thehydraulic power unit 130 that is in operation, the shutdown valve 180installed on the hydraulic line connected to the hydraulic power unit130 that is in operation is closed, and the shutdown valve 180 installedon the hydraulic line connected to the other hydraulic power unit 130 isopened, thereby making it possible to operate the other hydraulic powerunit 130.

As shown in FIG. 7, the lubricating motor 110 and the hydraulic motor120 may be connected to one hydraulic power unit 130. When thelubricating motor 110 and the hydraulic motor 120 receive the oil fromone hydraulic power unit 130 as shown in FIG. 7, the number of installedhydraulic power units 130 is decreased, such that an additional devicemay be decreased, thereby making it possible to simplify a systemconfiguration.

Here, since the lubricating motor 110 requires a smaller amount of oilthan an amount of oil required by the hydraulic motor 120, a pressureregulating valve (PRV) 193 is installed on the hydraulic line connectedto the lubricating motor 110 to regulate an amount of oil supplied tothe lubricating motor.

FIG. 8 is a view showing still another example of an apparatus forsupplying a fuel to an engine of a ship according to an embodiment ofthe invention.

As shown in FIG. 8, the apparatus for supplying a fuel to an engine of aship according to an embodiment of the invention is configured toinclude a high pressure pump 170 pressurizing an LNG and supplying thepressurized LNG to the engine, a hydraulic motor 120 driving the highpressure pump 170, and two hydraulic power units 130 supplying oil tothe hydraulic motor 120.

The hydraulic motor 120 is connected to the high pressure pump 170 todrive the high pressure pump 170. A driving shaft is connected betweenthe hydraulic motor 120 and the high pressure pump 170, and drivingforce of the hydraulic motor 120 may be transferred to the high pressurepump 170 through the driving shaft.

A hydraulic power unit 130 is a device supplying oil to the hydraulicmotor 120 in order to drive the hydraulic motor 120.

The hydraulic power unit 130 includes a hydraulic pump 131 and areservoir 132. The reservoir 132 is a storage tank storing the oiltherein. As shown in FIG. 8, the hydraulic motor 120 and the reservoir132 are connected to each other by a hydraulic line, and the hydraulicpump 131 is installed on the hydraulic line through which the oil flowsfrom the reservoir 132 to the hydraulic motor 120. The hydraulic pump131 supplies the oil stored in the reservoir 132 to the hydraulic motor120, and the oil drives the hydraulic motor 120 and then flows againinto the reservoir 132 through the hydraulic line.

As shown in FIG. 8, the hydraulic motor 120 may be connected to twohydraulic power units 130.

That is, since the hydraulic motor 120 is connected to the two hydraulicpower units 130, in the case in which one of the two hydraulic powerunits 130 may not be operated due to a fault, or the like, the other ofthe two hydraulic power units 130 is operated to supply the oil to thehydraulic motor 120, such that the hydraulic motor 120 may becontinuously operated normally.

As shown in FIG. 8, a shutdown valve 180 is installed on the hydraulicline connecting the hydraulic motor 120 and the hydraulic power unit 130to each other. When the hydraulic power unit 130 connected to thehydraulic line on which the corresponding shutdown valve 180 isinstalled is operated, the corresponding shutdown valve 180 is opened,and when the hydraulic power unit 130 connected to the hydraulic line onwhich the corresponding shutdown valve 180 is installed is not operated,the corresponding shutdown valve 180 is closed.

That is, in the case in which a first hydraulic power unit 130 and asecond hydraulic power unit 130 are connected to the hydraulic motor120, the shutdown valve 180 installed on the hydraulic line connected tothe first hydraulic power unit 130 is opened during a period in whichthe first hydraulic power unit 130 is operated, and the shutdown valve180 installed on the hydraulic line connected to the first hydraulicpower unit 130 is closed and the shutdown valve 180 installed on thehydraulic line connected to the second hydraulic power unit 130 isopened when a fault occurs in the first hydraulic power unit 130, suchthat the second hydraulic power unit 130 is operated.

In addition, a pressure gauge 190 is installed on the hydraulic line tosense whether or not a fault has occurred in the hydraulic power unit130. When the pressure indicated by the pressure gauge 190 exceeds anormal range, it is judged that a fault has occurred in the hydraulicpower unit 130 that is in operation, the shutdown valve 180 installed onthe hydraulic line connected to the hydraulic power unit 130 that is inoperation is closed, and the shutdown valve 180 installed on thehydraulic line connected to the other hydraulic power unit 130 isopened, thereby making it possible to operate the other hydraulic powerunit 130.

Since a load of the MEGI engine is variable, a speed of the highpressure pump supplying the fuel to the engine should be regulated, andsince a zone in which the high pressure pump is present is anexplosion-proof zone, it is dangerous to operate the high pressure pumpusing an electric motor. Therefore, in an embodiment of the invention, amethod for regulating a speed of a high pressure pump using a hydraulicmotor is provided.

FIG. 9 is a view showing an example of an apparatus for regulating aspeed of a high pressure pump of a ship according to an embodiment ofthe invention; FIG. 10 is a view showing another example of an apparatusfor regulating a speed of a high pressure pump of a ship according to anembodiment of the invention; and FIG. 11 is a view showing still anotherexample of an apparatus for regulating a speed of a high pressure pumpof a ship according to an embodiment of the invention.

As shown in FIGS. 9 to 11, the apparatus for regulating a speed of ahigh pressure pump of a ship according to an embodiment of the inventionis configured to include a hydraulic motor 210 and a hydraulic powerunit 220.

The hydraulic motor 210 is connected to the high pressure pump 250 todrive the high pressure pump 250 while regulating a speed of the highpressure pump 250. A driving shaft is connected between the hydraulicmotor 210 and the high pressure pump 250, and driving force of thehydraulic motor 210 may be transferred to the high pressure pump 250through the driving shaft.

The high pressure pump 250 supplies LNG to the engine through a highpressure vaporizer. However, since an amount of LNG required by theengine is variable, the speed of the high pressure pump 250 should beable to be regulated. Therefore, in an embodiment of the invention, aspeed of the hydraulic motor 210 is regulated to regulate the speed ofthe high pressure pump 250.

Since a zone in which the high pressure pump 250 is present is a dangerzone in which the possibility of explosion is present, a device usingelectricity, which may cause a spark, may not be installed in the dangerzone in order to secure safety. Therefore, in an embodiment of theinvention, the hydraulic motor 210 rather than an electric motor is usedas a driving apparatus of the high pressure pump 250, which isadvantageous in terms of maintenance and space utilization withoutinstalling the electric motor in the danger zone.

The hydraulic power unit 220, which is a device supplying the oil to thehydraulic motor 210 in order to drive the hydraulic motor 210, regulatesan amount of oil supplied to the hydraulic motor 210 to regulate thespeed of the hydraulic motor 210.

The hydraulic power unit 220 includes a hydraulic pump 221 or 222 and areservoir 223. The reservoir 223 is a storage tank storing the oiltherein. As shown in FIGS. 9 to 11, the hydraulic motor 210 and thereservoir 223 are connected to each other by hydraulic lines 240 and241, and the hydraulic pump 221 or 222 is installed on the hydraulicline 240 through which the oil flows from the reservoir 223 to thehydraulic motor 210. The hydraulic pump 221 or 222 supplies the oilstored in the reservoir 223 to the hydraulic motor 210, and the oildrives the hydraulic motor 210 and then flows again into the reservoir223 through the hydraulic line 241.

Here, in order to regulate the speed of the hydraulic motor 210, anamount of oil supplied to the hydraulic motor 210 should be regulated.

In FIGS. 9 and 10, a fixed displacement type hydraulic pump 221 isinstalled in the hydraulic power unit 220, and a hydraulic line 242branched from the hydraulic line 240 through which the oil flows fromthe reservoir 223 to the hydraulic motor 210 and again connected to thereservoir and a recirculation valve 230 are installed. That is, thefixed displacement type hydraulic pump 221 continuously pumps a constantamount of oil, and the recirculation valve 230 is regulated to regulatean amount of oil supplied to the hydraulic motor 210. For example, whena speed of the hydraulic motor 210 is to be increased, the recirculationvalve is closed to allow a large amount of oil to be supplied to thehydraulic motor 210, when a speed of the hydraulic motor 210 is to bedecreased, the recirculation valve is opened to allow a large amount ofoil to flow to the hydraulic line 242, thereby allowing a small amountof oil to be supplied to the hydraulic motor 210. Here, an opened degreeof the valve is regulated, thereby making it possible to regulate anamount of oil supplied to the hydraulic motor 210.

FIG. 9 is a view showing the case in which the recirculation valve isinstalled outside the hydraulic power unit 220, and FIG. 10 is a viewshowing the case in which the recirculation valve is installed insidethe hydraulic power unit 220.

In the case in which a worker uses the hydraulic power unit 220 thatincludes the fixed displacement type hydraulic pump 221 but does nothave the recirculation valve installed therein, he/she separatelyinstalls the recirculation valve 230 outside the hydraulic power unit220 as shown in FIG. 9, thereby making it possible to regulate an amountof oil supplied to the hydraulic motor 210.

Alternatively, the worker may use the hydraulic power unit 220 thatincludes the fixed displacement type hydraulic pump 221 and has therecirculation valve 230 installed therein, as shown in FIG. 10.

FIG. 11 shows the case in which the hydraulic power unit 220 includes avariable displacement type hydraulic pump 222. In FIG. 11, the variabledisplacement type hydraulic pump 222 is regulated to regulate an amountof oil pumped from the reservoir 223 by the variable displacement typehydraulic pump 222, thereby making it possible to regulate an amount ofoil supplied to the hydraulic motor 210.

Next, a method for regulating a speed of a high pressure pump of a shipaccording to an embodiment of the invention will be described withreference to FIGS. 12 and 13. FIG. 12 is a flow chart showing an exampleof a method for regulating a speed of a high pressure pump of a shipaccording to an embodiment of the invention; and FIG. 13 is a flow chartshowing another example of a method for regulating a speed of a highpressure pump of a ship according to an embodiment of the invention.

FIG. 12 shows a method for regulating a high pressure pump of a ship bythe apparatus for regulating a speed of a high pressure pump of a shipshown in FIGS. 9 and 10.

As shown in FIG. 12, the oil in the reservoir 223 of the hydraulic powerunit 220 is transferred toward the hydraulic line 240 by the hydraulicpump 221 (S410). Here, since the hydraulic pump 221 is the fixeddisplacement type hydraulic pump, it continuously transfers a constantamount of oil toward the hydraulic line 240.

Then, the recirculation valve 230 is regulated to regulate an amount ofoil supplied to the hydraulic motor 210 (S420). Here, the recirculationvalve 230 may be installed outside the hydraulic power unit 220 as shownin FIG. 9 or be installed inside the hydraulic power unit 220 as shownin FIG. 10. That is, the fixed displacement type hydraulic pump 221continuously transfers a constant amount of oil, and the recirculationvalve 230 is regulated to regulate an amount of oil supplied to thehydraulic motor 210. For example, when a speed of the hydraulic motor210 is to be increased, the recirculation valve is closed to allow alarge amount of oil to be supplied to the hydraulic motor 210, when aspeed of the hydraulic motor 210 is to be decreased, the recirculationvalve is opened to allow a small amount of oil to be supplied to thehydraulic motor 210. Here, an opened degree of the valve is regulated,thereby making it possible to regulate an amount of oil supplied to thehydraulic motor 210.

Then, a speed of the hydraulic motor 210 is regulated (S430) dependingon the regulation of the amount of oil, a speed of the high pressurepump 250 is regulated (S440) depending on the regulation of the speed ofthe hydraulic motor 210.

FIG. 13 shows a method for regulating a high pressure pump of a ship bythe apparatus for regulating a speed of a high pressure pump of a shipshown in FIG. 11.

As shown in FIG. 13, the oil in the reservoir is supplied to thehydraulic motor 210 while an amount of oil is regulated by the hydraulicpump 222 (S510). Here, since the hydraulic pump 222 is the variabledisplacement type hydraulic pump, it is regulated, thereby making itpossible to regulate an amount of oil supplied to the hydraulic motor210.

Then, a speed of the hydraulic motor 210 is regulated (S520) dependingon the regulation of the amount of oil, a speed of the high pressurepump 250 is regulated (S530) depending on the regulation of the speed ofthe hydraulic motor 210.

Referring back to FIGS. 4 and 5, components of the combustible materialtransferring apparatus shown in FIGS. 4 and 5 can be combined to anapparatus for supplying a fuel to an engine shown in FIGS. 6 to 13.

FIG. 4 is a view showing an example of a combustible materialtransferring apparatus driven by a hydraulic motor according to anembodiment of the invention. The combustible material transferringapparatus according to an embodiment of the invention shown in FIG. 4includes a pressurizing means 10 installed in a transferring pipe 2within a pressurizing zone 1 and pressurizing a combustible material totransfer the combustible material in one direction within thetransferring pipe 2 and a hydraulic motor 20, which is a driving meansinstalled together with the pressurizing means 10 within thepressurizing zone 1 and driving the pressurizing means 10.

As the pressurizing means 10, a pump may be used in the case oftransferring a combustible material in a liquid state, such as a LNG,and a compressor may be used in the case of transferring a combustiblematerial in a gas state such as a natural gas (BOG).

Since the pressurizing zone 1, which is a pump room or a compressorroom, is a zone in which the possibility of explosion is present due toleakage of the combustible material, a device using electricity, whichmay cause a spark, may not be installed in the pressurizing zone inorder to secure safety. Since the hydraulic motor 20 does not use theelectricity, it may be installed in the pressurizing zone 1.

As described above, the hydraulic motor is used instead of the electricmotor as a driving means for driving the pressurizing means 10 such asthe pump, the compressor, or the like, installed in the pressurizingzone 1, thereby making it possible to provide a combustible materialtransferring apparatus and method advantageous in terms of maintenanceand space utilization without installing the electric motor in thepressurizing zone 1 in which the possibility of explosion is present dueto the leakage of the combustible material.

A driving shaft 21 is connected between the hydraulic motor 20 and thepressurizing means 10, and driving force of the hydraulic motor 20 maybe transferred to the pressurizing means 10 through the driving shaft21.

In the combustible material transferring apparatus according to anembodiment of the invention shown in FIG. 4, a lubricating pump 40supplying lubricating oil to the hydraulic motor 20 installed in thepressurizing zone 1 and a lubricating oil pump hydraulic motor 50driving the lubricating oil pump 40 are installed together with thehydraulic motor 20 in the pressurizing zone 1.

In order to smoothly drive the hydraulic pump 20, lubrication betweenthe respective components that are operated is required. In addition,since a temperature of the LNG, which is the combustible material, is avery low temperature of approximately −163° C. at a room temperature, atemperature of the pressurizing means 10 becomes very low. Therefore,the hydraulic motor 20 installed closely to the pressurizing means 10and connected to the pressurizing means 10 through the driving shaft 21may also be affected by the low temperature. In the case in which anambient temperature is low, since viscosity of the lubricating oil isincreased, there is a risk that lubrication will not be performed well,such that circulation of the lubricating oil may be required.

Since the hydraulic motor 20 according to the present embodiment isconnected to the pressurizing means 10 pressurizing the combustiblematerial through the driving shaft 21, in embodiments, a structure inwhich the lubricating oil is circulated may be used instead a structurein which the lubricating oil stagnates in the hydraulic motor 20. Tothis end, the lubricating oil pump 40 and the lubricating oil pumphydraulic motor 50 are installed at positions spaced apart from thepressurizing means 10 and the hydraulic motor 20, respectively, withinthe pressurizing zone 1.

Similar to that the driving shaft 21 is connected between the hydraulicmotor 20 and the pressurizing means 10 so that the driving force of thehydraulic motor 20 may be transferred to the pressurizing means 10, adriving shaft 51 is connected between the lubricating oil pump hydraulicmotor 50 and the lubricating oil pump 40 so that driving force of thelubricating oil pump hydraulic motor 50 may be transferred to thelubricating oil pump 40.

In order to lubricate between the components included in the hydraulicmotor 20, the lubricating oil may be supplied into the hydraulic motor20 through a lubricating oil supplying line 41 extended from thelubricating oil pump 40 to the hydraulic motor 20 and may return to thelubricating oil pump 40 through a lubricating oil returning line 42extended from the hydraulic motor 20 to the lubricating oil pump 40.

Meanwhile, the supply of an operating fluid to the hydraulic motor 20and the lubricating oil pump hydraulic motor 50 may be simply performedby a hydraulic pressure generating apparatus that is already installedin a marine structure. However, according to the present embodiment, adedicated hydraulic pressure generating apparatus 53 for the hydraulicmotor 20 driving the pressurizing means 10 pressurizing the combustiblematerial and the lubricating oil pump hydraulic motor 50 driving thelubricating oil pump 40 is installed, such that the hydraulic motor 20and the lubricating oil pump hydraulic motor 50 may receive theoperating fluid.

The dedicated hydraulic pressure generating apparatus 53 includes afirst hydraulic pump 24 supplying the operating fluid to the hydraulicmotor 20, a second hydraulic pump 54 supplying the operating fluid tothe lubricating oil pump hydraulic motor 50, and a reservoir 52 storingthe operating fluid therein.

Two hydraulic pumps having the same specification may be included as thefirst hydraulic pump 24 in the hydraulic pressure generating apparatus53 in order to provide against a fault.

The operating fluid stored in the reservoir 52 may be pressurized by thefirst hydraulic pump 24, be supplied to the hydraulic motor 20 through afirst supplying line 25 to operate the hydraulic motor 20, and thenreturn again to the reservoir 52 through a first returning line 26. Aportion or all of the operating fluid returning through the firstreturning line 26 may be supplied directly toward an upper portion ofthe first hydraulic motor 24 of the first supplying line 25 withoutpassing through the reservoir 52, if necessary.

In addition, the operating fluid stored in the reservoir 52 may bepressurized by the second hydraulic pump 54, be supplied to thelubricating oil pump hydraulic motor 50 through a second supplying line55 to operate the lubricating oil pump hydraulic motor 50, and thenreturn again to the reservoir 52 through a second returning line 56. Aportion or all of the operating fluid returning through the secondreturning line 56 may be supplied directly toward an upper portion ofthe second hydraulic pump 54 of the second supplying line 55 withoutpassing through the reservoir 52, if necessary.

According to the present embodiment, a first drain line 27 used whendraining all of the operating fluid in the hydraulic motor 20 formaintenance of the hydraulic motor 20 may be installed. The first drainline 27 may be extended from the hydraulic motor 20, particularly, alower end portion of the hydraulic motor 20 to an outer portion of thereservoir 52 or the hydraulic pressure generating apparatus 53. Thefirst drain line 27 has a valve 28 installed thereon, and the valve 28is opened only when a drain work is performed, thereby draining theoperating fluid in the hydraulic motor 20 toward, for example, thereservoir 52.

In addition, according to the present embodiment, a second drain line 57used when draining all of the operating fluid in the lubricating oilpump hydraulic motor 50 for maintenance of the lubricating oil pumphydraulic motor 50 may be installed. The second drain line 57 may beextended from the lubricating oil pump hydraulic motor 50, particularly,a lower end portion of the lubricating oil pump hydraulic motor 50 to anouter portion of the reservoir 52 or the hydraulic pressure generatingapparatus 53. The second drain line 57 has a valve 58 installed thereon,and the valve 58 is opened only when a drain work is performed, therebydraining the operating fluid in the lubricating oil pump hydraulic motor50 toward, for example, the reservoir 52.

The hydraulic motor 20 and the lubricating oil pump hydraulic motor 50according to the present embodiment may be a speed variable hydraulicmotor of which a speed is variable. In the case of using the speedvariable hydraulic motor, there is no need to use a separatedeceleration apparatus. Therefore, the speed variable hydraulic motoroccupies a smaller installation space and is more advantageous in termsof maintenance as compared with an electric motor requiring adeceleration apparatus such as a deceleration gear, or the like.

FIG. 5 is a view showing another example of a combustible materialtransferring apparatus driven by a hydraulic motor according to anembodiment of the invention.

The combustible material transferring apparatus according to anembodiment of the invention shown in FIG. 5 includes a pressurizingmeans 10 installed in a transferring pipe 2 within a pressurizing zone 1and pressurizing a combustible material to transfer the combustiblematerial in one direction within the transferring pipe 2 and a hydraulicmotor 20, which is a driving means installed together with thepressurizing means 10 within the pressurizing zone 1 and driving thepressurizing means 10.

As the pressurizing means 10, a pump may be used in the case oftransferring a combustible material in a liquid state, such as a LNG,and a compressor may be used in the case of transferring a combustiblematerial in a gas state such as a natural gas (BOG).

Since the pressurizing zone 1, which is a pump room or a compressorroom, is a zone in which the possibility of explosion is present due toleakage of the combustible material, a device using electricity, whichmay cause a spark, may not be installed in the pressurizing zone inorder to secure safety. Since the hydraulic motor 20 does not use theelectricity, it may be installed in the pressurizing zone 1.

As described above, the hydraulic motor is used instead of the electricmotor as a driving means for driving the pressurizing means 10 such asthe pump, the compressor, or the like, installed in the pressurizingzone 1, thereby making it possible to provide a combustible materialtransferring apparatus and method advantageous in terms of maintenanceand space utilization without installing the electric motor in thepressurizing zone 1 in which the possibility of explosion is present dueto the leakage of the combustible material.

A driving shaft 21 is connected between the hydraulic motor 20 and thepressurizing means 10, and driving force of the hydraulic motor 20 maybe transferred to the pressurizing means 10 through the driving shaft21.

The combustible material transferring apparatus according to anembodiment of the invention shown in FIG. 5 utilizes an operating fluidused to drive the hydraulic motor 20 as lubricating oil supplied to thehydraulic motor 20, unlike an embodiment shown in FIG. 4. Therefore, thecombustible material transferring apparatus shown in FIG. 5 does notneed the lubricating oil pump 40 and the lubricating oil pump hydraulicmotor 50 shown in FIG. 4.

Meanwhile, the supply of the operating fluid to the hydraulic motor 20may be simply performed by a hydraulic pressure generating apparatusthat is already installed in a marine structure. However, according tothe present embodiment, the hydraulic motor 20 driving the pressurizingmeans 10 pressurizing the combustible material and a dedicated hydraulicpressure generating apparatus 53 for supplying the lubricating oil tothe hydraulic motor 20 are installed, such that the hydraulic motor 20may receive the operating fluid and the lubricating oil.

The dedicated hydraulic pressure generating apparatus 53 includes afirst hydraulic pump 24 supplying the operating fluid to the hydraulicmotor 20, a second hydraulic pump 54 supplying the operating fluid asthe lubricating oil to the hydraulic motor 20, and a reservoir 52storing the operating fluid therein.

Two hydraulic pumps having the same specification may be included as thefirst hydraulic pump 24 in the hydraulic pressure generating apparatus53 in order to provide against a fault.

The operating fluid stored in the reservoir 52 may be pressurized by thefirst hydraulic pump 24, be supplied to the hydraulic motor 20 through afirst supplying line 25 to operate the hydraulic motor 20, and thenreturn again to the reservoir 52 through a first returning line 26. Aportion or all of the operating fluid returning through the firstreturning line 26 may be supplied directly toward an upper portion ofthe first hydraulic motor 24 of the first supplying line 25 withoutpassing through the reservoir 52, if necessary.

In addition, the operating fluid stored in the reservoir 52 may bepressurized by the second hydraulic pump 54, be supplied as thelubricating oil to the hydraulic motor 20 through a second supplyingline 55, and then return again to the reservoir 52 through a secondreturning line 56. A portion or all of the operating fluid returningthrough the second returning line 56 may be supplied directly toward anupper portion of the second hydraulic pump 54 of the second supplyingline 55 without passing through the reservoir 52, if necessary.

According to the present embodiment, a first drain line 27 used whendraining all of the operating fluid in the hydraulic motor 20 formaintenance of the hydraulic motor 20 may be installed. The first drainline 27 may be extended from the hydraulic motor 20, particularly, alower end portion of the hydraulic motor 20 to an outer portion of thereservoir 52 or the hydraulic pressure generating apparatus 53. Thefirst drain line 27 has a valve 28 installed thereon, and the valve 28is opened only when a drain work is performed, thereby draining theoperating fluid in the hydraulic motor 20 toward, for example, thereservoir 52.

In addition, according to the present embodiment, a lubricating oildrain line 67 used when draining all of the lubricating oil used in thehydraulic motor for maintenance of the hydraulic motor 20 may beinstalled. The lubricating oil drain line 67 may be extended from thehydraulic motor 20, particularly, a lubricating oil circulating part inthe hydraulic motor 20 to an outer portion of the reservoir 52 or thehydraulic pressure generating apparatus 53. The lubricating oil drainline 67 has a valve 68 installed thereon, and the valve 68 is openedonly when a drain work is performed, thereby draining the operatingfluid as the lubricating oil in the hydraulic motor 20 toward, forexample, the reservoir 52.

The hydraulic motor 20 according to the present embodiment may be aspeed variable hydraulic motor of which a speed is variable. In the caseof using the speed variable hydraulic motor, there is no need to use aseparate deceleration apparatus. Therefore, the speed variable hydraulicmotor occupies a smaller installation space and is more advantageous interms of maintenance as compared with an electric motor requiring adeceleration apparatus such as a deceleration gear, or the like.

According to embodiments of the invention, the apparatus for supplying afuel to an engine of a ship uses the hydraulic motor that does notgenerate an electric spark as a driving source of the high pressuremotor installed in a danger zone, thereby making it possible tominiaturize and lighten all devices, and the apparatus for supplying afuel to an engine of a ship is installed in an explosion-proof zonewithout an additional device, thereby making it possible to supply powerand lubricating oil to the high pressure pump.

In addition, according to embodiments of the invention, an extrahydraulic power unit is provided, thereby making it possible to alwaysdrive the high pressure pump without an additional delay even in thecase in which a fault occurs in the hydraulic power unit that is inoperation.

Further, according to embodiments of the invention, hydraulic pressureis supplied to the lubricating motor and the hydraulic motor using onehydraulic power unit, thereby making it possible to decrease the numberof separate additional devices.

In addition, the apparatus for regulating a speed of a high pressurepump of a ship uses the hydraulic motor that does not generate anelectric spark as a driving source of the high pressure motor installedin a danger zone, thereby making it possible to miniaturize and lightenall devices, and the apparatus for regulating a speed of a high pressurepump of a ship is installed in an explosion-proof zone without anadditional device, thereby making it possible to regulate a speed of thehigh pressure pump.

Turning to FIG. 14 which is a diagram of a fuel gas supply apparatus ina vessel, the vessel includes a high-pressure engine and a low-pressureengine therein.

A vessel may include a plurality of engines as needed and generallyincludes at least one main engine (for example, an MEGI engine) forpropulsion and at least one sub-engine (for example, a DF engine) forpower generation. Since the main engine generally requires ahigher-pressure fuel gas than the sub-engine, the sub-engine is referredto as a low-pressure engine 1020 and the main engine is referred to as ahigh-pressure engine 1030 in the following description.

In general, the International Maritime Organization (IMO) regulates theemission of nitrogen oxides (NO_(X)) and sulfur oxides (SO_(X)) amongexhaust gases of vessels and these days, also tries to regulate theemission of carbon dioxide (CO₂). Particularly, the issue of theregulation of nitrogen oxides (NO_(X)) and sulfur oxides (SO_(X)) wasraised by the Prevention of Marine Pollution from Ships (MARPOL)protocol in 1997. After eight years, the protocol met requirements foreffectuation and entered into force in May 2005. Currently, theregulation is in force as a compulsory provision.

Therefore, in order to meet such provisions, a variety of methods havebeen introduced to reduce the emission of nitrogen oxides (NO_(X)). Asone of these methods, a high-pressure natural gas injection engine for amarine structure such as an LNG carrier, for example, an MEGI engine hasbeen developed and used. The MEGI engine is being spotlighted as anext-generation eco-friendly engine capable of reducing emission ofcarbon dioxide by 23% or more, nitrogen compounds by 80% or more, andsulfur compounds by 95% or more, as compared with a diesel engine havingthe same output.

Such an MEGI engine may be disposed in plants or vessels such as an LNGcarrier which transports LNG while storing the LNG in a storage tankcapable of withstanding cryogenic temperatures. In this case, the MEGIengine uses natural gas as fuel and requires a high pressure of about150 to 400 bara (absolute pressure) for gas supply, depending upon aload thereof.

The MEGI engine may be directly coupled to a propeller for propulsion.To this end, the MEGI engine may be a two-stroke engine rotating at alow speed. That is, the MEGI engine is a low-speed two-strokehigh-pressure natural gas injection engine.

The fuel gas supply apparatus may be configured such that fuel gassupplied through a fuel transfer line L1 from a fuel tank is supplied tothe low-pressure engine 1020 through a low-pressure gas supply line L2and to the high-pressure engine 1030 through a high-pressure gas supplyline L3.

When LNG is used as fuel gas, the LNG in a liquid state is heated toundergo phase change into a gaseous state and then supplied to anengine. To this end, a low-pressure gas supply system 1021 is disposedat the low-pressure gas supply line L2, through which the fuel gas issupplied to the low-pressure engine 1020, and a high-pressure gas supplysystem 1031 is disposed at the high-pressure gas supply line L3, throughwhich the fuel gas is supplied to the high-pressure engine 1030.

The low-pressure gas supply system 1021 includes a low-pressuregasification unit 1022, and the high-pressure gas supply system 1031includes a high-pressure pump 1032 and a high-pressure gasification unit1036. A transfer pump for transferring LNG stored in the fuel tank isdisposed inside or outside the fuel tank. The pressure of fuel gasrequired for the low-pressure engine 1020 is similar to that of fuel gaspressurized by the transfer pump and thus, a pump need not beadditionally disposed in the low-pressure gas supply system 1021.However, the pressure of fuel gas required for the high-pressure engine1030 is higher than that of the fuel gas pressurized by the transferpump and thus, the high-pressure pump 1032 needs to be additionallydisposed in the high-pressure gas supply system 1031 to pressurize thefuel gas pressurized by the transfer pump to a higher pressure of about150 to 400 bara.

The high-pressure pump 1032 may include a pumping unit 1033 forpressurizing and discharging introduced LNG, a drive unit 1034 (forexample, a motor) for driving the pumping unit 1033, and a connectingshaft 1035 for interconnecting the pumping unit 1033 and the drive unit1034 to transmit power. Facilities, such as pumps or compressors, aswell as the high-pressure pump 1032 have a seal structure. However, LNGcan leak through the seal structure.

Since LNG leaked from the pump can cause explosion or fire, a space(namely, a first space 1001) for receiving the high-pressure pump 1032is distinguished as a danger zone, and explosion proof products with ahigher grade have to be used for the facilities arranged together withthe high-pressure pump 1032 in the first space or room 1001. In the casewhere the low-pressure gas supply system 1021 and the high-pressure gassupply system 1031 are all arranged together with the high-pressure pump1032 in the first space 1001 as shown in FIG. 14, explosion proofproducts have to be used for the facilities, such as the low-pressuregasification unit 1022 included in the low-pressure gas supply system1021 and the high-pressure gasification unit 1036 included in thehigh-pressure gas supply system 1031, thereby causing increase infacility costs.

Hereinafter, embodiments of the invention will be described in detailwith reference to FIGS. 15 to 17. In addition, it should be understoodthat the following embodiments may be modified in various differentforms and the invention is not limited thereto.

FIG. 15 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention, which is disposed in a vessel having ahigh-pressure engine and a low-pressure engine therein.

A vessel may include a plurality of engines therein as needed andgenerally includes at least one high-pressure engine 1030 (for example,an MEGI engine) provided for propulsion and at least one low-pressureengine 1020 (for example, a DF engine) provided for power generation.The high-pressure engine 1030 requires a higher-pressure fuel gas thanthe low-pressure engine 1020.

As used herein, the term “vessel” is a concept including plants, such asan LNG FPSO, an Oil FPSO, an LNG FSRU, and a BMPP, as well as vessels,such as a liquefied gas carrier, an LNG RV, and a container ship.

In addition, the term “fuel gas” as used herein is a concept including agas that is stored as cargo in a storage tank and supplied to an enginewhen necessary, as well as a gas that is stored in a fuel tank for fuelsupply to various types of engines provided to a vessel for propulsionand power generation.

In the fuel gas supply apparatus according to this embodiment, fuel gassupplied through a fuel transfer line L1 from a fuel tank is supplied tothe low-pressure engine 1020 through a low-pressure gas supply line L2and to the high-pressure engine 1030 through a high-pressure gas supplyline L3.

A low-pressure gas supply system 1021 is provided to the low-pressuregas supply line L2 through which the fuel gas is supplied to thelow-pressure engine 1020, and a high-pressure gas supply system 1031 isprovided to the high-pressure gas supply line L3 through which the fuelgas is supplied to the high-pressure engine 1030.

The low-pressure gas supply system 1021 includes a low-pressuregasification unit 1022, and the high-pressure gas supply system 1031includes a high-pressure pump 1032 and a high-pressure gasification unit1036. Examples of facilities included in the low-pressure gas supplysystem 1021 in addition to the low-pressure gasification unit 1022 mayinclude various types of devices used for supply of the fuel gas to thelow-pressure engine and a control unit for controlling the devices.Examples of facilities included in the high-pressure gas supply system1031 in addition to the high-pressure pump 1032 and the high-pressuregasification unit 1036 may include various types of devices used forsupply of the fuel gas to the high-pressure engine and a control unitfor controlling the devices.

A transfer pump for transferring LNG stored in the fuel tank is disposedinside or outside the fuel tank. The pressure of fuel gas required forthe low-pressure engine 1020 is similar to that of fuel gas pressurizedby the transfer pump and thus, a pump need not be additionally disposedin the low-pressure gas supply system 1021. However, the pressure of afuel gas required for the high-pressure engine 1030 is higher than thatof the fuel gas pressurized by the transfer pump and thus, thehigh-pressure pump 1032 needs to be additionally disposed in thehigh-pressure gas supply system 1031 to pressurize the fuel gaspressurized by the transfer pump to a higher pressure of about 150 to400 bara.

The LNG which is pressurized to a higher pressure by the high-pressurepump 1032 and then heated in the high-pressure gasification unit 1036 isin a super-critical state and thus, cannot be distinguished into gas orliquid. Therefore, the term “gasification” as used in the high-pressuregasification unit 1036 should be understood as a meaning of heating LNGto a temperature required for the high-pressure engine.

The high-pressure pump 1032, which is typically a reciprocating pump,may include a pumping unit 1033 for pressurizing and then dischargingthe introduced LNG, a drive unit 1034 (for example, a motor) for drivingthe pumping unit 1033, and a connecting shaft 1035 for interconnectingthe pumping unit 1033 and the drive unit 1034 to transmit power.

Since the LNG leaked from the pump can cause explosion or fire, a space(namely, a first space 1001) for receiving the high-pressure pump 1032is distinguished as a danger zone, and explosion proof products of ahigher grade must be used for the facilities arranged together with thehigh-pressure pump 1032 in the first space 1001.

According to the embodiment of the invention shown in FIG. 15, thelow-pressure gas supply system 1021 is disposed in a separate space,namely, a second space 1002 distinguished by a partition wall 1003 fromthe high-pressure gas supply system 1031 including the high-pressurepump 1032. Since the facilities, such as the low-pressure gasificationunit 1022, included in the low-pressure gas supply system 1021 aredisposed in the space separated from the high-pressure pump 1032, anenhanced explosion grade need not to be applied thereto, therebyreducing costs for manufacturing facilities. However, the facilities ofthe high-pressure gas supply system 1031 arranged together with thehigh-pressure pump 1032 in the first space 1001 must be manufactured byapplying an enhanced explosion grade.

FIG. 16 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention, which is disposed in a vessel having ahigh-pressure engine and a low-pressure engine therein.

The following description is focused on a difference between the fuelgas supply apparatuses according to the above embodiments. In addition,like elements to those of the embodiment are denoted by like numerals,and detailed descriptions thereof will be omitted.

The fuel gas supply apparatus according to the embodiment is the same asthe fuel gas supply apparatus according to the embodiment in that thefuel gas supply apparatus includes a low-pressure gas supply system 1021provided to a low-pressure gas supply line L2 for supplying fuel gas toa low-pressure engine 1020 and including a low-pressure gasificationunit 1022 and a high-pressure gas supply system 1031 provided to ahigh-pressure gas supply line L3 for supplying fuel gas to ahigh-pressure engine 1030 and including a high-pressure pump 1032 and ahigh-pressure gasification unit 1036, and the high-pressure pump 1032includes a pumping unit 1033, a drive unit 1034, and a connecting shaft1035.

However, according to the embodiment, among facilities included in thehigh-pressure gas supply system 1031, only the high-pressure pump 1032is disposed in a first space 1001, and the rest of the facilities exceptfor the high-pressure pump 1032, for example, the high-pressuregasification unit 1036, is arranged together with the low-pressure gassupply system 1021 in a space separated from the first space 1001 by apartition wall 1003, namely, in a second space or room 1002. Since thefacilities, such as the low-pressure gasification unit 1022, included inthe low-pressure gas supply system 1021 and, among the facilitiesincluded in the high-pressure gas supply system 1031, the rest of thefacilities except for the high-pressure pump 1032, for example thehigh-pressure gasification unit 1036, are disposed in the spaceseparated from the high-pressure pump 1032, an enhanced explosion gradeneeds not to be applied thereto, thereby reducing costs required formanufacturing facilities. In embodiment, the room 1001 is gas-tightlyseparated from the room 1002, and the partition wall 1003 is a gas-tightwall to inhibit air or gas in the room 1001 from flowing into the room1002 through the partition wall 1003.

FIG. 17 is a diagram of a fuel gas supply apparatus according to anembodiment of the invention, which is disposed in a vessel having ahigh-pressure engine and a low-pressure engine therein.

The following description is focused on a difference between the fuelgas supply apparatuses according to the above embodiments. In addition,like elements to those of the embodiment are denoted by like numerals,and detailed descriptions thereof will be omitted.

The fuel gas supply apparatus according to the embodiment is the same asthe fuel gas supply apparatus according to the embodiment in that thefuel gas supply apparatus includes a low-pressure gas supply system 1021provided to a low-pressure gas supply line L2 for supplying fuel gas toa low-pressure engine 1020 and including a low-pressure gasificationunit 1022 and a high-pressure gas supply system 1031 provided to ahigh-pressure gas supply line L3 for supplying fuel gas to ahigh-pressure engine 1030 and including a high-pressure pump 1032 and ahigh-pressure gasification unit 1036, and the high-pressure pump 1032includes a pumping unit 1033, a drive unit 1034, and a connecting shaft1035.

However, according to the embodiment, among facilities included in thehigh-pressure gas supply system 1031, only the high-pressure pump 1032is disposed in a first space 1001, and the rest of the facilities exceptfor the pumping unit 1033 of the high-pressure pump 1032, for examplethe high-pressure gasification unit 1036 and the drive unit 1034 of thehigh-pressure pump 1032, are arranged together with the low-pressure gassupply system 1021 in a space separated from the first space 1001 by apartition wall 1003, namely, in a second space 1002. Since thefacilities, such as the low-pressure gasification unit 1022, included inthe low-pressure gas supply system 1021 and, among the facilitiesincluded in the high-pressure gas supply system 1031, the rest of thefacilities except for the pumping unit 1033 of the high-pressure pump1032, for example the high-pressure gasification unit 1036 and the driveunit 1034 of the high-pressure pump 1032, are disposed in the spaceseparated from the pumping unit 1033 of the high-pressure pump 1032, anenhanced explosion grade needs not to be applied thereto, therebyreducing costs required for manufacturing facilities.

The drive unit 1034 of the high-pressure pump 1032 does not pass the LNGtherethrough and thus leakage of LNG does not occur. Accordingly, whenonly the pumping unit 1033 having the LNG introduced thereinto andpressurized and discharged thereby, among the facilities of thehigh-pressure pump 1032, is disposed within a danger zone, an enhancedexplosion grade needs not to be applied to the drive unit 1034 of thehigh-pressure pump 1032 disposed in the separate space divided by thepartition wall 1003.

According to the embodiment, a bearing 4 having a sealing function maybe disposed in the partition wall 1003 such that the connecting shaft1035 interconnecting the pumping unit 1033 and the drive unit 1034 maypass therethrough.

According to the embodiments of the invention, since the high-pressurepump 1032, particularly the pumping unit 1033 of the high-pressure pump1032, through which fuel gas can leak is disposed in the first space001, which is a danger zone divided by the partition wall 1003, it ispossible to minimize an influence on the rest facilities even uponleakage of the fuel gas. Thus, explosion proof products of a low grademay be used for the facilities which are not disposed in the space 1,thereby reducing initial installation costs.

A drive unit such as an electric motor may be banned from spaces, inwhich the pump is disposed, according to regulations, irrespective of anexplosion proof grade. In the case where a fuel gas supply apparatus isconstituted as in the embodiment of the invention, only the pumping unit1033 of the high-pressure pump 1032 is disposed in the first space 1001,and the drive unit 1034 of the high-pressure pump 1032, namely, anelectric motor, is disposed in the second space 1002 separated from thefirst space 1001 by the partition wall 1003. Therefore, the fuel gassupply apparatus can be unfettered by regulations.

Ship with Fuel Gas Engine and Fuel Gas Supply System

FIG. 18 shows a ship according to embodiments of the invention.Referring to FIGS. 18 and 19, a ship 2010 includes first and second fueltanks 2020 2020, a fuel supply system, a high-pressure engine 2030 and alow-pressure engine 2035.

Fuel Tank and Fuel

The fuel tank 2020 contains fuel in a liquid state. In one embodiment,the fuel contained in the tanks 2020 may be liquefied natural gas (LNG)in liquid state. In another embodiment, the fuel may be liquefiedpetroleum gas (LPG) in liquid state or ethane in liquid state. In otherembodiments, the fuel may be any liquefied hydrocarbon fuel.

The ship 2010 includes a low-pressure pump 2110 to supply the fuel via aconduit to a high-pressure pump or a vaporizer 2130 which are discussedbelow. The low-pressure pump 2110 is enclosed in each tank 2020 andsubmerged in the fuel in liquid state contained in the tank.

High-Pressure Engine

In embodiments, the high-pressure engine 2030 is used to propel the ship2010. The high-pressure fuel engine 2030 may be a supercritical fuelengine that combustions the fuel in a supercritical state. For this, thefuel is pressurized to have a pressure in a range from about 150 barabsolute (bar(a)) to about 400 bar(a), and heated to be in asupercritical state. And then, the fuel is supplied to the supercriticalfuel engine. In one embodiment, the supercritical fuel engine may be anM-type Electronic Gas Injection (MEGI) engine.

Low-Pressure Engine

In embodiments, the low-pressure engine 2035 is used to generateelectricity and heat that are used in the ship 2010. The low-pressureengine 2035 may be a vapor fuel engine that burns the fuel in avaporized state. For this, the fuel is pumped from the fuel tank 2020 bya low-pressure pump 2110 contained in the fuel tank, and heated to be ina vaporized state. And then, the fuel in a vaporized state is suppliedto the low-pressure fuel engine 2035. The fuel in a vaporized state mayhave a pressure in a range from about 2 bar(a) to about 20 bar(a). Inembodiments, the fuel in a vaporized state may have a pressure in arange from about 6 bar(a) to about 10 bar(a). In one embodiment, thelow-pressure engine or vapor fuel engine 2035 may be a dual-fueldiesel-electric (DFDE) engine. In another embodiment, the low-pressureengine 2035 may be a gas turbine engine.

Supercritical Fuel Supply

For supplying fuel in a supercritical state, in embodiments, the ship2010 includes a high-pressure fuel pump 2112 and a heater 2114. The fuelpump 2112 is in fluid communication with the fuel tank 2020 andpressurizes the fuel from the fuel tank 2020 to a pressure in a rangefrom about 150 bar(a) to about 400 bar(a). The heater 2114 is in fluidcommunication with the fuel pump 2112 and heats the pressurized fuelfrom the fuel pump 2112 to a supercritical state of the fuel. The fuelin a supercritical state is supplied to the supercritical fuel engine2030 and combusted in the engine 2030 which propels the ship 2010.

Hydraulic System

In embodiments, to operate the fuel pump 2112, a hydraulic system and anelectric motor 2126 are provided. The hydraulic system includes ahydraulic pump 2120 and a hydraulic motor 2122 connected to thehydraulic pump 2120 through hydraulic fluid conduits 2128. The hydraulicpump 2120 converts mechanical power produced by the electric motor 2126into a pressurized flow of a hydraulic fluid. The pressurized flow ofthe hydraulic fluid is transferred to the hydraulic motor 2122. In turn,the hydraulic motor 2122 converts the pressurized flow from thehydraulic pump 2120 into torque to power the fuel pump 2112 such thatthe fuel pump 2112 pressurizes the fuel. In embodiments, the hydraulicsystem further includes a container or reservoir 2124 for containing thehydraulic fluid. The container 2124 is in fluid communication with thehydraulic pump 2120 and the hydraulic motor 2122.

Fuel Pump and Hydraulic Motor

In the illustrated embodiments, the fuel pump 2112 and the hydraulicmotor 2122 may be separate from each other and connected to each othervia a rotating shaft. In other embodiments, the fuel pump 2112 and thehydraulic motor 2122 are built in an integrated body.

In embodiments, the fuel pump 2112 is a piston pump including a piston.The fuel pump 2112 further includes a rotation-to-reciprocationconverter which coverts torque from the hydraulic motor 2122 toreciprocating motion of the piston.

Lubrication System

In embodiments, the ship 2010 includes a lubrication pump forlubricating a fuel pump 2112 module which includes the fuel pump 2112and the hydraulic motor 2122. In embodiments, the fuel pump 2112 moduleincludes various mechanisms which may be lubricated. The lubricant pumpis to pump lubricant to the fuel pump 2112, the hydraulic motor 2122 andother mechanisms in the fuel pump 2112 module.

Referring to FIGS. 4, 18 and 19, in embodiments, to operate thelubricant pump, the ship 2010 includes a secondary electric motor, asecondary hydraulic pump and a secondary hydraulic motor. The secondaryhydraulic pump converts torque from the electric motor 2126 into apressurized flow of a hydraulic fluid. The secondary hydraulic motor isin fluid communication with the secondary hydraulic pump and configuredto convert the pressurized flow from the secondary hydraulic pump intotorque to power the lubricant pump.

Vaporized Fuel Supply System

The ship 2010 includes a vaporized fuel supply system which includes avaporizer 2130 and a mist separator 2131. The vaporizer 2130 is in fluidcommunication with the fuel tank 2020 and vaporizes the fuel from thefuel tank 2020 by heating the fuel. The mist separator 2131 is in fluidcommunication between the vaporizer 2130 and the vapor fuel engine 2035.The mist separator 2131 removes mists contained in the fuel receivedfrom the vaporizer 2130 and returns the removed mists to the vaporizer2130.

Compartments

Referring to FIGS. 18-21, in embodiments, components of the fuel supplysystem are enclosed in some compartments. The ship 2010 includes fueltank compartments 2045, a fuel pump compartment 2040, a fuel processingcompartment 2040, a hydraulic pump compartment 2060, an enginecompartment and other various compartments. As shown in FIGS. 20 and 21,freight containers 2500 may be loaded over the fuel tank compartments2045, the fuel pump compartment 2040, and the fuel processingcompartment 2040.

Each of the fuel tank compartments encloses one of the fuel tanks 2020.The fuel pump compartment 2040 encloses the fuel pump 2112 and thehydraulic motor 2122. The hydraulic pump compartment 2060 encloses thehydraulic pump 2120, the container 2124 and the electric motor 2126. Thefuel processing compartment 2050 encloses the heater 2114 of thesupercritical state fuel supply system, and further encloses thevaporizer 2130 and the mist separator 2131 of the vaporized fuel supplysystem.

In embodiments, each of the compartments is air-tightly separated fromimmediately neighboring compartments by walls 2032, 2034, 2036, 2038. Inone embodiment, the fuel pump compartment 2040 includes air-tight wallsto form an enclosed space of the compartment 2040 for substantiallyinhibiting air in the compartment 2040 from flowing into the neighboringcompartments through the walls. However, as discussed below, air in thecompartment 2040 can be discharged to outside the ship through a conduitwithout flowing into the neighboring compartments. In anotherembodiment, the fuel processing compartment 2050 includes air-tightwalls to form an enclosed space of the compartment 2050 forsubstantially inhibiting air in the compartment 2050 from flowing intothe neighboring compartments through the walls. However, as discussedbelow, air in the compartment 2050 can be discharged to outside the shipthrough a conduit without flowing into the neighboring compartments.

In embodiments, the fuel pump compartment 2040 is air-tightly separatedfrom the fuel processing compartment 2050 by air-tight walls includingan air-tight partitioning wall 2032. As a result, the fuel pump 2112 andthe hydraulic motor 2122 are air-tightly isolated from the heater 2114,the vaporizer 2130 and the mist separator 2131. Also, the fuel pumpcompartment 2040 is air-tightly separated from other neighboring tankcompartments, for example, the fuel tank compartments 2045 by the wall2034.

In embodiments, the fuel pump compartment 2040 is air-tightly separatedfrom the hydraulic pump compartment 2060 by air-tight walls. Thus, thefuel pump 2112 and the hydraulic motor 2122 are air-tightly isolatedfrom the hydraulic pump 2120 and the electric motor 2126.

Location of Compartments and Walls Between Compartments

In embodiments, the ship 2010 includes a hull 2012 and a deck 2014placed over the hull. The fuel processing compartment 2050 and thehigh-pressure pump compartment are located above the deck 2014 of theship 2010. The hydraulic pump compartment 2060 is located under thedeck. In one embodiment, the fuel processing compartment 2050 and thefuel pump compartment 2040 are adjacent to each other and air-tightlyseparated from each other by a partitioning wall located between thecompartments. A down-stream line 2042 from the fuel pump 2112 to theheater 2114 passes through one of the partitioning wall. In alternativeembodiment, the down-stream line from the fuel pump 2112 to the heater2114 does not pass through the partitioning wall 2032, but extendsthrough other walls to go around the wall 2032 as illustrated with abroken line 2043 in FIG. 19.

In one embodiment, the ship 2010 includes a cofferdam 2038 interposedbetween the fuel pump compartment 2040 and the hydraulic pumpcompartment 2060. The hydraulic fluid conduits 2128 may pass through thecofferdam 2038. In another embodiment, the hydraulic fluid conduits donot pass through the cofferdam 2038 but extend through other walls to goaround the cofferdam 2038 as illustrated with a broken line 2129 in FIG.19.

Air Circulation System for Compartments

Referring to FIG. 20, in embodiments, the fuel pump compartment 2040includes a first air inlet 2642 and a first air outlet 2644. The firstair inlet 2642 receives air from outside the ship 2010 through a firstair intake conduit 2646. The first air outlet 2644 is used to dischargeair from the fuel pump compartment 2040 to outside the ship 2010 througha first air discharge conduit 2648. The air from outside the ship 2010enters the fuel pump compartment 2040 through the first air inlet 2642without mixing with air from another compartment of the ship 2010through.

The first air discharge conduit 2648 receives air from the first airoutlet 2644 of the fuel pump compartment 2040 and transfer it to a firstfuel leak detector 2650 which is installed at an end portion of thefirst air discharge conduit 2648. A first blower 2652 is installed atthe end portion of the first air discharge conduit 2648 to generate anair flow from outside the ship 2010 to outside the ship 2010 through thefirst air intake conduit 2646, the fuel pump compartment 2040 and thefirst air discharge conduit 2648.

Referring to FIG. 21, in embodiments, the fuel processing compartment2050 includes a second air inlet 2752 and a second air outlet 2754. Thesecond air inlet 2752 receives air from outside the ship 2010 through asecond air intake conduit 2756. The second air outlet 2754 is used todischarge air from the fuel processing compartment 2050 to the outsidethe ship 2010 through a second air discharge conduit 2758. The air fromthe outside the ship 2010 enters the fuel processing compartment 2050through the second air inlet 2752 without mixing with air from anothercompartment of the ship 2010.

The second air discharge conduit 2758 receives air from the second airoutlet 2754 of the fuel processing compartment 2050 and transfer it to asecond fuel leak detector 2760 which is installed at an end portion ofthe second air discharge conduit 2758. A second blower 2762 is installedat the end portion of the second air discharge conduit 2758 to generatean air flow from outside the ship 2010 to outside the ship 2010 throughthe second air intake conduit 2756, the fuel processing compartment 2050and the second air discharge conduit 2758.

Avoiding Transfer of Air in One Compartment to Another Compartment

In embodiments, further to air-tight partitioning between the fuel pumpcompartment 2040 and the fuel processing compartment 2050, the first andsecond air intake conduits 2648 and 2758 are separate from each other.Thus, air in the fuel pump compartment 2040 is not mixed with that inthe fuel processing compartment 2050 through the first and second airintake conduits. Likewise, the first air discharge conduit 2648 and thesecond air discharge conduit 2758 are isolated from each other. Thus,air in the fuel pump compartment 2040 is not mixed with that in the fuelprocessing compartment 2050 through the first and second air dischargeconduits. Above configurations are provided to avoid or minimize risk oftransferring air between the fuel pump compartment 2040 and the fuelpump compartment 2040 through the conduits. In alternative embodiments,the first and second air intake conduits may be connected to an commonintake conduit that receives air from outside of the ship and transferthe air to the first and second air intake conduits as long as air inthe fuel pump compartment 2040 is not transferred to the fuel processingcompartment 2050 through the first and second air intake conduits.

Leakage of Fuel in Compartments

In embodiments, the ship 2010 may include a controller which can stopthe operation of the devices or components enclosed in the fuel pumpcompartment 2040 when the leak detector 2650 detects leakage of the fuelgas. Only the first blower 2652 is operated to circulate air anddischarges leaked fuel gas from the fuel pump compartment 2040. Like theair circulation configuration for the fuel pump compartment 2040, thecontroller may stop the devices enclosed in the fuel processingcompartment 2050 when the leak detector 2760 detects leakage of the fuelgas. Only the second blower 2762 is operated to circulate air anddischarges leaked fuel gas from the fuel processing compartment 2050.

In embodiments, when the concentration of the fuel gas detected by thefirst detector is greater than a lower explosive limit (LEL, or lowerflammability limit) of the fuel, the devices enclosed in the fuel pumpcompartment 2040 may be stopped by the controller or manually. In oneembodiment, when the concentration of the fuel gas with respect to airis greater than a predetermined level which ranges about 30% to about40%, the devices enclosed in the fuel pump compartment 2040 may bestopped by the controller or manually. Same or similar leakageconditions may be applied to the air circulation configuration for thefuel processing compartment 2050.

Location of Lubrication System

Referring to FIGS. 4 and 19, in embodiments, the lubrication pump andthe secondary hydraulic motor are located in the fuel pump compartment2040. The secondary hydraulic pump and the secondary electric motor arelocated in the hydraulic pump compartment 2060. Thus, the fuel pump 2112and the hydraulic motor 2122 are air-tightly isolated from the secondaryhydraulic pump and the secondary electric motor.

In the illustrated embodiments, lubricant conduits are enclosed in thefuel pump compartment 2040. Contrastingly, hydraulic fluid conduitsconnecting between the secondary hydraulic motor and the secondaryhydraulic pump may extend through the air-tight partitioning wallbetween the fuel pump compartment 2040 and the hydraulic pumpcompartment 2060.

In other embodiments as shown in FIG. 5, the lubricant pump is locatedin the hydraulic pump compartment 2040. In the embodiments illustratedin FIG. 5, lubricant conduits connecting between the lubricant pump andthe fuel pump 2112 module may extend through the air-tight partitioningwall between the fuel pump compartment 2040 and the hydraulic pumpcompartment 2060.

Heater and Vaporizer

Referring to FIG. 19, in embodiments, the heater 2114 includes a firstheat exchanger which heats the pressurized fuel being transferredbetween the fuel pump 2112 and the supercritical fuel engine. Thevaporizer 2130 includes a second heat exchanger that heats the fuel fromthe at least one fuel tank 2020 to change the fuel in a vaporized state.

The ship 2010 further includes a third heat exchanger 2150 and heatmedium conduits. The first, second and third heat exchangers and theheat medium form a heat medium circuit in which a heat mediumcirculates. In one embodiment, the heat medium may be glycol water. Inthe heat medium circuit, the heat medium receives heat from another heatmedium at the third heat exchanger. The other heat medium transfers heatfrom a heat source, for example, the MEGI engine 2030 or the DFDE engine2035. At the first heat exchanger, the heat medium transfers heat to thepressurized fuel transferred from the fuel pump 2112 such that thetemperature of the fuel is raised and the pressurized fuel becomes intoa supercritical state. At the second heat exchanger, the heat mediumtransfers heat to the fuel from the fuel tank 2020 thereby vaporizingthe fuel.

In embodiments, the first, second and third heat exchangers and the heatmedium conduits are enclosed in the fuel processing compartment 2060.Thus, the fuel pump 2112 and the hydraulic motor 2122 are air-tightlyisolated from the first, second and third heat exchangers.

It is apparent to those skilled in the art that the invention is notlimited to the above embodiments and various modifications or variationscan be made without departing from the scope of the invention.

What is claimed is:
 1. A ship comprising: at least one fuel tankcontaining fuel; a fuel pump in fluid communication with the at leastone fuel tank and configured to pressurize fuel from the at least onefuel tank; a heater in fluid communication with the fuel pump andconfigured to heat pressurized fuel from the fuel pump; an engine influid communication with the heater and configured to consume the fuelfrom the heater; a fuel pump compartment enclosing the fuel pump and ahydraulic motor for powering the fuel pump such that fuel from the atleast one fuel tank is pressurized within the fuel pump compartment,wherein no electric motor is enclosed within the fuel pump compartment;and a fuel processing compartment enclosing the heater such that thepressurized fuel travels from the fuel pump compartment to the fuelprocessing compartment and is heated within the fuel processingcompartment, wherein the fuel pump compartment is air-tightly separatedfrom the fuel processing compartment by at least one air-tight wall suchthat the fuel pump and the hydraulic motor are air-tightly isolated fromthe heater.
 2. The ship of claim 1, wherein the fuel pump is configuredto pressurize fuel from the at least one fuel tank to a pressure in arange from 150 bar absolute (bar(a)) to 400 bar(a), wherein the enginecomprises a supercritical fuel engine configured to consume the fuel ina supercritical state, wherein the heater is configured to heat thepressurized fuel from the fuel pump to a supercritical state of thefuel, wherein the fuel pump compartment comprises a first air inletconfigured to receive air from outside the ship and a first air outletconfigured to discharge air from the fuel pump compartment, wherein theair from the outside the ship is to enter the fuel pump compartmentthrough the first air inlet substantially free of mixing with air fromanother compartment of the ship.
 3. The ship of claim 1, furthercomprising a hydraulic pump located outside the fuel pump compartmentand configured to convert mechanical power into a pressurized flow of ahydraulic fluid, wherein the pressurized flow is supplied to thehydraulic motor enclosed within the fuel pump compartment, wherein thehydraulic motor is configured to convert the pressurized flow intotorque to power the fuel pump.
 4. The ship of claim 3, furthercomprising: lubricant conduits in fluid communication with the hydraulicpump and configured to supply at least part of the fluid as lubricant toeither or both of the fuel pump and the hydraulic motor, wherein thelubricant conduits pass through at least one air-tight wall; and alubricant pump configured to pump the lubricant to send the lubricant toeither or both of the fuel pump and the hydraulic motor enclosed in thefuel pump compartment, wherein the lubricant pump is located outside thefuel pump compartment.
 5. The ship of claim 3, wherein the ship furthercomprises hydraulic fluid conduits interconnecting the hydraulic pumpand the hydraulic motor to form a closed loop of the hydraulic fluid,wherein the hydraulic fluid conduits air-tightly pass through the atleast one air-tight wall of the fuel pump compartment, wherein the fuelpump compartment comprises a first air inlet configured to receive airfrom outside the ship and a first air outlet configured to discharge airfrom the fuel pump compartment, wherein the air from the outside theship is to enter the fuel pump compartment through the first air inletsubstantially free of mixing with air from another compartment of theship.
 6. The ship of claim 5, further comprising: an electric motorconfigure to power pumping of the hydraulic pump; and a hydraulic pumpcompartment enclosing the hydraulic pump and the electric motor suchthat the hydraulic fluid is pressurized within the hydraulic pumpcompartment and sent to the fuel pump compartment, wherein the fuel pumpcompartment is air-tightly separated from the hydraulic pump compartmentby at least one air-tight wall such that the fuel pump and the hydraulicmotor are air-tightly isolated from the hydraulic pump.
 7. The ship ofclaim 6, further comprising: a lubricant pump configured to pumplubricant to either or both of the fuel pump and the hydraulic motorenclosed in the fuel pump compartment; a secondary hydraulic pumpcomprising an electric motor and configured to convert torque from theelectric motor into a pressurized flow of a hydraulic fluid; and asecondary hydraulic motor in fluid communication with the secondaryhydraulic pump and configured to convert the pressurized flow from thesecondary hydraulic pump into torque to power the lubricant pump,wherein the lubricant pump is enclosed in the fuel pump compartment,wherein the secondary hydraulic pump is enclosed in the hydraulic pumpcompartment, wherein the secondary hydraulic motor is enclosed in thefuel pump compartment.
 8. The ship of claim 6, wherein the shipcomprises a hull and a deck placed over the hull, wherein the fuelprocessing compartment and the fuel pump compartment are located abovethe deck of the ship, wherein the hydraulic pump compartment is locatedunder the deck, wherein the ship further comprises.
 9. The ship of claim6, further comprising a cofferdam or another distinct compartmentinterposed between the fuel pump compartment and the hydraulic pumpcompartment, wherein the hydraulic fluid conduits pass through thecofferdam or the other distinct compartment.
 10. The ship of claim 1,further comprising a cofferdam interposed between the fuel pumpcompartment and the hydraulic pump compartment, wherein the hydraulicfluid conduits does not pass through the cofferdam and instead goesaround the cofferdam, wherein the fuel processing compartment and thefuel pump compartment are adjacent to each other and separated by the atleast one wall only without any intervening compartment or cofferdambetween the fuel pump compartment and the fuel processing compartment,wherein a down-stream line from the fuel pump to the heater does notpass through the at least one wall and instead goes around the at leastone wall such that the down-stream line passes through another wall ofthe fuel pump compartment and another wall of the fuel processingcompartment.
 11. The ship of claim 1, wherein the fuel pump compartmentcomprises a first air inlet configured to receive air from outside theship and a first air outlet configured to discharge air from the fuelpump compartment, wherein the air from the outside the ship is to enterthe fuel pump compartment through the first air inlet substantially freeof mixing with air from another compartment of the ship.
 12. The ship ofclaim 11, wherein the fuel processing compartment comprises a second airinlet configured to receive air from outside the ship and a second airoutlet configured to discharge air from the fuel processing compartment,wherein the air from the outside the ship is to enter the fuelprocessing compartment through the second air inlet substantially freeof mixing with air from another compartment of the ship.
 13. The ship ofclaim 12, further comprising: a first air intake conduit configured toreceive air from outside the ship and transfer the air to the first airinlet; and a second air intake conduit configured to receive air fromoutside the ship and transfer the air to the second air inlet, whereinthe first and second air intake conduits are separate from each otherand are not interconnected.
 14. The ship of claim 12, furthercomprising: a first air discharge conduit configured to receive air fromthe first air outlet of the fuel pump compartment to outside the ship; afirst leak detector configured to be exposed to the air discharged fromthe fuel pump compartment and to detect leakage of fuel within the fuelpump compartment; a second air discharge conduit configured to receiveair from the second outlet of the fuel processing compartment outsidethe ship; and a second leak detector configured to be exposed to airdischarged from the fuel processing compartment and to detect leakage offuel within the fuel pump compartment.
 15. The ship of claim 1, whereinthe fuel pump and the hydraulic motor enclosed in the fuel pumpcompartment are built in an integrated body, wherein the fuel pumpcomprises a piston and a rotation-to-reciprocation converter configuredto convert torque from the hydraulic motor to reciprocating motion ofthe piston.
 16. The ship of claim 1, wherein the ship comprises a hulland a deck placed over the hull, wherein the fuel processing compartmentand the fuel pump compartment are adjacent to each other and separatedby the at least one wall without any intervening compartment orcofferdam between the fuel pump compartment and the fuel, processingcompartment, wherein a down-stream line from the fuel pump to the heaterpass through the at least one wall.
 17. The ship of claim 1, wherein theheater comprises a heat exchanger configured to heat the pressurizedfuel from the fuel pump, wherein the hydraulic pump comprises anelectric motor configured to generate mechanical energy to power pumpingto generate the pressurized flow of hydraulic fluid.
 18. The ship ofclaim 1, further comprising: a vaporizer in fluid communication with theat least one fuel tank and configured to vaporize the fuel from the atleast one fuel tank; and a vapor fuel engine in fluid communication withthe vaporizer and configured to consume the fuel from the vaporizer inits vapor state, wherein the vaporizer is enclosed in the fuelprocessing compartment, wherein the fuel from the at, least one fueltank is transferred to the vaporizer without going through the fuel pumpcompartment.
 19. The ship of claim 18, further comprising a mistseparator in fluid communication with the vaporizer and configured toremove mists contained in the fuel from the vaporizer before the fuel issent to the vapor fuel engine, wherein the vaporizer comprises a heatexchanger configured to heat the fuel from the at least one fuel tank toprovide the vaporized state of the fuel, wherein the mist separator isalso enclosed in the fuel processing compartment.
 20. The ship of claim1, further comprising a lubricant pump configured to pump lubricant toeither or both of the fuel pump and the hydraulic motor enclosed in thefuel pump compartment, wherein the lubricant pump is enclosed within oroutside the fuel pump compartment.